diff --git a/.whitesource b/.whitesource
new file mode 100644
index 000000000..5ef5902b9
--- /dev/null
+++ b/.whitesource
@@ -0,0 +1,8 @@
+##########################################################
+#### WhiteSource "Bolt for Github" configuration file ####
+##########################################################
+
+# Configuration #
+#---------------#
+ws.repo.scan=true
+vulnerable.check.run.conclusion.level=success
\ No newline at end of file
diff --git a/InterfaceStubGenerator.Core/GeneratedInterfaceStubTemplate.mustache b/InterfaceStubGenerator.Core/GeneratedInterfaceStubTemplate.mustache
index 3b458f4cc..c1780e617 100644
--- a/InterfaceStubGenerator.Core/GeneratedInterfaceStubTemplate.mustache
+++ b/InterfaceStubGenerator.Core/GeneratedInterfaceStubTemplate.mustache
@@ -61,11 +61,7 @@ namespace {{Namespace}}
         {{#MethodList}}
 
         /// <inheritdoc />
-        public virtual {{ReturnType}} {{Name}}{{#MethodTypeParameters}}<{{.}}>
-            {{/MethodTypeParameters}}({{ArgumentListWithTypes}})
-            {{#MethodConstraintClauses}}
-            {{.}}
-            {{/MethodConstraintClauses}}
+        {{ReturnType}} {{InterfaceName}}{{#TypeParameters}}<{{.}}>{{/TypeParameters}}.{{Name}}{{#MethodTypeParameters}}<{{.}}>{{/MethodTypeParameters}}({{ArgumentListWithTypes}})
         {
             {{#IsRefitMethod}}
             var arguments = new object[] { {{ArgumentList}} };
diff --git a/InterfaceStubGenerator.Core/InterfaceStubGenerator.cs b/InterfaceStubGenerator.Core/InterfaceStubGenerator.cs
index ff5444e08..c7bc907db 100644
--- a/InterfaceStubGenerator.Core/InterfaceStubGenerator.cs
+++ b/InterfaceStubGenerator.Core/InterfaceStubGenerator.cs
@@ -4,7 +4,6 @@
 using System.Linq;
 using System.Reflection;
 using System.Text;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -92,6 +91,7 @@ public ClassTemplateInfo GenerateClassInfoForInterface(InterfaceDeclarationSynta
             ret.InterfaceName = GetInterfaceName(interfaceTree.Identifier);
             ret.GeneratedClassSuffix = ret.InterfaceName.Replace(".", "");
             ret.Modifiers = interfaceTree.Modifiers.Select(t => t.ValueText).FirstOrDefault(m => m == "public" || m == "internal");
+            ret.BaseClassNames = interfaceTree.BaseList?.Types.Select(t => t.ToString()).ToList();
 
             var ns = parent as NamespaceDeclarationSyntax;
             ret.Namespace = ns?.Name?.ToString() ?? $"AutoGenerated{ret.GeneratedClassSuffix}";
@@ -114,6 +114,8 @@ public ClassTemplateInfo GenerateClassInfoForInterface(InterfaceDeclarationSynta
                                               var mti = new MethodTemplateInfo
                                               {
                                                   Name = x.Identifier.Text,
+                                                  InterfaceName = ret.InterfaceName,
+                                                  TypeParameters = ret.TypeParameters,
                                                   ReturnType = x.ReturnType.ToString(),
                                                   ArgumentList = string.Join(",",
                                                                              x.ParameterList.Parameters
@@ -134,7 +136,6 @@ public ClassTemplateInfo GenerateClassInfoForInterface(InterfaceDeclarationSynta
                                                       mti.MethodTypeParameterList = string.Join(", ", typeParameters.Select(p => $"typeof({p.Identifier.ValueText})"));
                                                       mti.MethodTypeParameterNames = $"{string.Join(", ", typeParameters.Select(p => $"{{typeof({p.Identifier.ValueText}).AssemblyQualifiedName}}"))}";
                                                   }
-                                                  mti.MethodConstraintClauses = x.ConstraintClauses.ToFullString().Trim();
                                               }
                                               return mti;
                                           })
@@ -181,9 +182,20 @@ public TemplateInformation GenerateTemplateInfoForInterfaceList(List<InterfaceDe
                 UsingList = usings.ToList()
             };
 
+            AddInheritedMethods(ret);
+
             return ret;
         }
 
+        private static void AddInheritedMethods(TemplateInformation ret)
+        {
+            foreach (var c in ret.ClassList.Where(c => c.BaseClassNames != null && c.BaseClassNames.Any()))
+            {
+                var methodsToAdd = ret.ClassList.Where(oc => c.BaseClassNames.Contains(oc.InterfaceName)).SelectMany(oc => oc.MethodList);
+                c.MethodList.AddRange(methodsToAdd);
+            }
+        }
+
         public void GenerateWarnings(List<InterfaceDeclarationSyntax> interfacesToGenerate)
         {
             var missingAttributeWarnings = interfacesToGenerate
@@ -240,6 +252,7 @@ public class ClassTemplateInfo
         public string ConstraintClauses { get; set; }
         public string GeneratedClassSuffix { get; set; }
         public string InterfaceName { get; set; }
+        public List<string> BaseClassNames { get; set; }
         public List<MethodTemplateInfo> MethodList { get; set; }
         public string Modifiers { get; set; }
         public string Namespace { get; set; }
@@ -255,9 +268,10 @@ public class MethodTemplateInfo
         public string Name { get; set; }
         public string ReturnType { get; set; }
         public string MethodTypeParameters { get; set; }
-        public string MethodConstraintClauses { get; set; }
         public string MethodTypeParameterList { get; set; }
         public string MethodTypeParameterNames { get; set; }
+        public string InterfaceName { get; set; }
+        public string TypeParameters { get; set; }
     }
 
     public class TemplateInformation
diff --git a/README.md b/README.md
index 60b16a79e..9ac783073 100644
--- a/README.md
+++ b/README.md
@@ -633,6 +633,69 @@ Which can be used like this:
 // than one type (unless you have a different domain for each type)
 var api = RestService.For<IReallyExcitingCrudApi<User, string>>("http://api.example.com/users"); 
 ``` 
+### Interface inheritance
+
+When multiple services that need to be kept separate share a number of APIs, it is possible to leverage interface inheritance to avoid having to define the same Refit methods multiple times in different services:
+
+```csharp
+public interface IBaseService
+{
+    [Get("/resources")]
+    Task<Resource> GetResource(string id);
+}
+
+public interface IDerivedServiceA : IBaseService
+{
+    [Delete("/resources")]
+    Task DeleteResource(string id);
+}
+
+public interface IDerivedServiceB : IBaseService
+{
+    [Post("/resources")]
+    Task<string> AddResource([Body] Resource resource);
+}
+```
+
+In this example, the `IDerivedServiceA` interface will expose both the `GetResource` and `DeleteResource` APIs, while `IDerivedServiceB` will expose `GetResource` and `AddResource`.
+
+#### Headers inheritance
+
+When using inheritance, existing header attributes will passed along as well, and the inner-most ones will have precedence:
+
+```csharp
+[Headers("User-Agent: AAA")]
+public interface IAmInterfaceA
+{
+    [Get("/get?result=Ping")]
+    Task<string> Ping();
+}
+
+[Headers("User-Agent: BBB")]
+public interface IAmInterfaceB : IAmInterfaceA
+{
+    [Get("/get?result=Pang")]
+    [Headers("User-Agent: PANG")]
+    Task<string> Pang();
+
+    [Get("/get?result=Foo")]
+    Task<string> Foo();
+}
+```
+
+Here, `IAmInterfaceB.Pang()` will use `PANG` as its user agent, while `IAmInterfaceB.Foo` and `IAmInterfaceB.Ping` will use `BBB`.
+Note that if `IAmInterfaceB` didn't have a header attribute, `Foo` would then use the `AAA` value inherited from `IAmInterfaceA`.
+If an interface is inheriting more than one interface, the order of precedence is the same as the one in which the inherited interfaces are declared:
+
+```csharp
+public interface IAmInterfaceC : IAmInterfaceA, IAmInterfaceB
+{
+    [Get("/get?result=Foo")]
+    Task<string> Foo();
+}
+```
+
+Here `IAmInterfaceC.Foo` would use the header attribute inherited from `IAmInterfaceA`, if present, or the one inherited from `IAmInterfaceB`, and so on for all the declared interfaces.
 
 ### Using HttpClientFactory
 
diff --git a/Refit.Tests/InheritedInterfacesApi.cs b/Refit.Tests/InheritedInterfacesApi.cs
new file mode 100644
index 000000000..24a7c46b2
--- /dev/null
+++ b/Refit.Tests/InheritedInterfacesApi.cs
@@ -0,0 +1,27 @@
+using System.Threading.Tasks;
+using Refit; // InterfaceStubGenerator looks for this
+using static System.Math; // This is here to verify https://github.com/paulcbetts/refit/issues/283
+
+namespace Refit.Tests
+{
+    [Headers("User-Agent: Refit Integration Tests")]
+    public interface IAmInterfaceA
+    {
+        [Get("/get?result=Ping")]
+        Task<string> Ping();
+    }
+
+    [Headers("User-Agent: Refit Integration Tests")]
+    public interface IAmInterfaceB
+    {
+        [Get("/get?result=Pong")]
+        Task<string> Pong();
+    }
+
+    [Headers("User-Agent: Refit Integration Tests")]
+    public interface IAmInterfaceC : IAmInterfaceB, IAmInterfaceA
+    {
+        [Get("/get?result=Pang")]
+        Task<string> Pang();
+    }
+}
diff --git a/Refit.Tests/InterfaceStubGenerator.cs b/Refit.Tests/InterfaceStubGenerator.cs
index 1b6a62bac..479852da3 100644
--- a/Refit.Tests/InterfaceStubGenerator.cs
+++ b/Refit.Tests/InterfaceStubGenerator.cs
@@ -27,9 +27,11 @@ public void GenerateInterfaceStubsSmokeTest()
             var result = fixture.GenerateInterfaceStubs(new[] {
                 IntegrationTestHelper.GetPath("RestService.cs"),
                 IntegrationTestHelper.GetPath("GitHubApi.cs"),
+                IntegrationTestHelper.GetPath("InheritedInterfacesApi.cs"),
             });
 
             Assert.Contains("IGitHubApi", result);
+            Assert.Contains("IAmInterfaceC", result);
         }
 
         [Fact]
@@ -126,6 +128,32 @@ public void GenerateTemplateInfoForInterfaceListSmokeTest()
             Assert.Equal(12, result.ClassList.Count);
         }
 
+        [Fact]
+        public void GenerateTemplateInfoForInheritedInterfacesListSmokeTest()
+        {
+            var file = CSharpSyntaxTree.ParseText(File.ReadAllText(IntegrationTestHelper.GetPath("InheritedInterfacesApi.cs")));
+            var fixture = new InterfaceStubGenerator();
+
+            var input = file.GetRoot().DescendantNodes()
+                .OfType<InterfaceDeclarationSyntax>()
+                .ToList();
+
+            var result = fixture.GenerateTemplateInfoForInterfaceList(input);
+            Assert.Equal(3, result.ClassList.Count);
+
+            var inherited = result.ClassList.First(c => c.InterfaceName == "IAmInterfaceC");
+
+            Assert.Equal(3, inherited.MethodList.Count);
+            var methodNames = inherited.MethodList.Select(m => m.Name).ToList();
+
+            Assert.Contains("Ping", methodNames);
+            Assert.Contains("Pong", methodNames);
+            Assert.Contains("Pang", methodNames);
+
+            Assert.Equal("IAmInterfaceC", inherited.InterfaceName);
+            Assert.Equal("IAmInterfaceC", inherited.GeneratedClassSuffix);
+        }
+
         [Fact]
         public void RetainsAliasesInUsings()
         {
diff --git a/Refit.Tests/RefitStubs.Net46.cs b/Refit.Tests/RefitStubs.Net46.cs
index fda73a626..f3d0ad3d3 100644
--- a/Refit.Tests/RefitStubs.Net46.cs
+++ b/Refit.Tests/RefitStubs.Net46.cs
@@ -73,7 +73,7 @@ public AutoGeneratedIAmARefitInterfaceButNobodyUsesMe(HttpClient client, IReques
         }
 
         /// <inheritdoc />
-        public virtual Task RefitMethod()
+        Task IAmARefitInterfaceButNobodyUsesMe.RefitMethod()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("RefitMethod", new Type[] {  });
@@ -81,7 +81,7 @@ public virtual Task RefitMethod()
         }
 
         /// <inheritdoc />
-        public virtual Task AnotherRefitMethod()
+        Task IAmARefitInterfaceButNobodyUsesMe.AnotherRefitMethod()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("AnotherRefitMethod", new Type[] {  });
@@ -89,13 +89,13 @@ public virtual Task AnotherRefitMethod()
         }
 
         /// <inheritdoc />
-        public virtual Task NoConstantsAllowed()
+        Task IAmARefitInterfaceButNobodyUsesMe.NoConstantsAllowed()
         {
             throw new NotImplementedException("Either this method has no Refit HTTP method attribute or you've used something other than a string literal for the 'path' argument.");
         }
 
         /// <inheritdoc />
-        public virtual Task SpacesShouldntBreakMe()
+        Task IAmARefitInterfaceButNobodyUsesMe.SpacesShouldntBreakMe()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("SpacesShouldntBreakMe", new Type[] {  });
@@ -103,7 +103,7 @@ public virtual Task SpacesShouldntBreakMe()
         }
 
         /// <inheritdoc />
-        public virtual Task ReservedWordsForParameterNames(int @int,string @string,float @long)
+        Task IAmARefitInterfaceButNobodyUsesMe.ReservedWordsForParameterNames(int @int,string @string,float @long)
         {
             var arguments = new object[] { @int,@string,@long };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReservedWordsForParameterNames", new Type[] { typeof(int),typeof(string),typeof(float) });
@@ -135,7 +135,7 @@ public AutoGeneratedIAmHalfRefit(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IAmHalfRefit.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -143,13 +143,125 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IAmHalfRefit.Get()
         {
             throw new NotImplementedException("Either this method has no Refit HTTP method attribute or you've used something other than a string literal for the 'path' argument.");
         }
     }
 }
 
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceA : IAmInterfaceA
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceA(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceA.Ping()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Ping", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceB : IAmInterfaceB
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceB(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceB.Pong()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pong", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceC : IAmInterfaceC
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceC(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceC.Pang()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pang", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceA.Ping()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Ping", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceB.Pong()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pong", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
 namespace Refit.Tests
 {
     using Refit.Tests.RefitInternalGenerated;
@@ -173,7 +285,7 @@ public AutoGeneratedIApiWithDecimal(HttpClient client, IRequestBuilder requestBu
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetWithDecimal(decimal value)
+        Task<string> IApiWithDecimal.GetWithDecimal(decimal value)
         {
             var arguments = new object[] { value };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetWithDecimal", new Type[] { typeof(decimal) });
@@ -205,7 +317,7 @@ public AutoGeneratedIBodylessApi(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IBodylessApi.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -213,7 +325,7 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IBodylessApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -221,7 +333,7 @@ public virtual Task Get()
         }
 
         /// <inheritdoc />
-        public virtual Task Head()
+        Task IBodylessApi.Head()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Head", new Type[] {  });
@@ -256,7 +368,7 @@ public AutoGeneratedIBoringCrudApi(HttpClient client, IRequestBuilder requestBui
         }
 
         /// <inheritdoc />
-        public virtual Task<T> Create(T paylod)
+        Task<T> IBoringCrudApi<T, TKey>.Create(T paylod)
         {
             var arguments = new object[] { paylod };
             var func = requestBuilder.BuildRestResultFuncForMethod("Create", new Type[] { typeof(T) });
@@ -264,7 +376,7 @@ public virtual Task<T> Create(T paylod)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<T>> ReadAll()
+        Task<List<T>> IBoringCrudApi<T, TKey>.ReadAll()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReadAll", new Type[] {  });
@@ -272,7 +384,7 @@ public virtual Task<List<T>> ReadAll()
         }
 
         /// <inheritdoc />
-        public virtual Task<T> ReadOne(TKey key)
+        Task<T> IBoringCrudApi<T, TKey>.ReadOne(TKey key)
         {
             var arguments = new object[] { key };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReadOne", new Type[] { typeof(TKey) });
@@ -280,7 +392,7 @@ public virtual Task<T> ReadOne(TKey key)
         }
 
         /// <inheritdoc />
-        public virtual Task Update(TKey key,T payload)
+        Task IBoringCrudApi<T, TKey>.Update(TKey key,T payload)
         {
             var arguments = new object[] { key,payload };
             var func = requestBuilder.BuildRestResultFuncForMethod("Update", new Type[] { typeof(TKey),typeof(T) });
@@ -288,7 +400,7 @@ public virtual Task Update(TKey key,T payload)
         }
 
         /// <inheritdoc />
-        public virtual Task Delete(TKey key)
+        Task IBoringCrudApi<T, TKey>.Delete(TKey key)
         {
             var arguments = new object[] { key };
             var func = requestBuilder.BuildRestResultFuncForMethod("Delete", new Type[] { typeof(TKey) });
@@ -320,7 +432,7 @@ public AutoGeneratedIBrokenWebApi(HttpClient client, IRequestBuilder requestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<bool> PostAValue(string derp)
+        Task<bool> IBrokenWebApi.PostAValue(string derp)
         {
             var arguments = new object[] { derp };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostAValue", new Type[] { typeof(string) });
@@ -352,7 +464,7 @@ public AutoGeneratedIGitHubApi(HttpClient client, IRequestBuilder requestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task<User> GetUser(string userName)
+        Task<User> IGitHubApi.GetUser(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUser", new Type[] { typeof(string) });
@@ -360,7 +472,7 @@ public virtual Task<User> GetUser(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserObservable(string userName)
+        IObservable<User> IGitHubApi.GetUserObservable(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservable", new Type[] { typeof(string) });
@@ -368,7 +480,7 @@ public virtual IObservable<User> GetUserObservable(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserCamelCase(string userName)
+        IObservable<User> IGitHubApi.GetUserCamelCase(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserCamelCase", new Type[] { typeof(string) });
@@ -376,7 +488,7 @@ public virtual IObservable<User> GetUserCamelCase(string userName)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<User>> GetOrgMembers(string orgName)
+        Task<List<User>> IGitHubApi.GetOrgMembers(string orgName)
         {
             var arguments = new object[] { orgName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetOrgMembers", new Type[] { typeof(string) });
@@ -384,7 +496,7 @@ public virtual Task<List<User>> GetOrgMembers(string orgName)
         }
 
         /// <inheritdoc />
-        public virtual Task<UserSearchResult> FindUsers(string q)
+        Task<UserSearchResult> IGitHubApi.FindUsers(string q)
         {
             var arguments = new object[] { q };
             var func = requestBuilder.BuildRestResultFuncForMethod("FindUsers", new Type[] { typeof(string) });
@@ -392,7 +504,7 @@ public virtual Task<UserSearchResult> FindUsers(string q)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> GetIndex()
+        Task<HttpResponseMessage> IGitHubApi.GetIndex()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndex", new Type[] {  });
@@ -400,7 +512,7 @@ public virtual Task<HttpResponseMessage> GetIndex()
         }
 
         /// <inheritdoc />
-        public virtual IObservable<string> GetIndexObservable()
+        IObservable<string> IGitHubApi.GetIndexObservable()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndexObservable", new Type[] {  });
@@ -408,7 +520,7 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task<User> NothingToSeeHere()
+        Task<User> IGitHubApi.NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  });
@@ -416,7 +528,7 @@ public virtual Task<User> NothingToSeeHere()
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
+        Task<ApiResponse<User>> IGitHubApi.NothingToSeeHereWithMetadata()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHereWithMetadata", new Type[] {  });
@@ -424,7 +536,7 @@ public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> GetUserWithMetadata(string userName)
+        Task<ApiResponse<User>> IGitHubApi.GetUserWithMetadata(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserWithMetadata", new Type[] { typeof(string) });
@@ -432,7 +544,7 @@ public virtual Task<ApiResponse<User>> GetUserWithMetadata(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<ApiResponse<User>> GetUserObservableWithMetadata(string userName)
+        IObservable<ApiResponse<User>> IGitHubApi.GetUserObservableWithMetadata(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservableWithMetadata", new Type[] { typeof(string) });
@@ -440,7 +552,7 @@ public virtual IObservable<ApiResponse<User>> GetUserObservableWithMetadata(stri
         }
 
         /// <inheritdoc />
-        public virtual Task<User> CreateUser(User user)
+        Task<User> IGitHubApi.CreateUser(User user)
         {
             var arguments = new object[] { user };
             var func = requestBuilder.BuildRestResultFuncForMethod("CreateUser", new Type[] { typeof(User) });
@@ -448,7 +560,7 @@ public virtual Task<User> CreateUser(User user)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> CreateUserWithMetadata(User user)
+        Task<ApiResponse<User>> IGitHubApi.CreateUserWithMetadata(User user)
         {
             var arguments = new object[] { user };
             var func = requestBuilder.BuildRestResultFuncForMethod("CreateUserWithMetadata", new Type[] { typeof(User) });
@@ -484,7 +596,7 @@ public AutoGeneratedIHttpBinApi(HttpClient client, IRequestBuilder requestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(TParam param,THeader header)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.Get(TParam param,THeader header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TParam),typeof(THeader) });
@@ -492,7 +604,7 @@ public virtual Task<TResponse> Get(TParam param,THeader header)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> GetQuery(TParam param)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.GetQuery(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQuery", new Type[] { typeof(TParam) });
@@ -500,7 +612,7 @@ public virtual Task<TResponse> GetQuery(TParam param)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> GetQueryWithIncludeParameterName(TParam param)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.GetQueryWithIncludeParameterName(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQueryWithIncludeParameterName", new Type[] { typeof(TParam) });
@@ -508,8 +620,7 @@ public virtual Task<TResponse> GetQueryWithIncludeParameterName(TParam param)
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> GetQuery1<TValue>
-            (TParam param)
+        Task<TValue> IHttpBinApi<TResponse, TParam, THeader>.GetQuery1<TValue>(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQuery1", new Type[] { typeof(TParam) }, new Type[] { typeof(TValue) });
@@ -541,7 +652,7 @@ public AutoGeneratedIHttpContentApi(HttpClient client, IRequestBuilder requestBu
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpContent> PostFileUpload(HttpContent content)
+        Task<HttpContent> IHttpContentApi.PostFileUpload(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostFileUpload", new Type[] { typeof(HttpContent) });
@@ -549,7 +660,7 @@ public virtual Task<HttpContent> PostFileUpload(HttpContent content)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<HttpContent>> PostFileUploadWithMetadata(HttpContent content)
+        Task<ApiResponse<HttpContent>> IHttpContentApi.PostFileUploadWithMetadata(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostFileUploadWithMetadata", new Type[] { typeof(HttpContent) });
@@ -581,7 +692,7 @@ public AutoGeneratedResponseTestsIMyAliasService(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<TestAliasObject> GetTestObject()
+        Task<TestAliasObject> ResponseTests.IMyAliasService.GetTestObject()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetTestObject", new Type[] {  });
@@ -613,7 +724,7 @@ public AutoGeneratedAuthenticatedClientHandlerTestsIMyAuthenticatedService(HttpC
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetUnauthenticated()
+        Task<string> AuthenticatedClientHandlerTests.IMyAuthenticatedService.GetUnauthenticated()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUnauthenticated", new Type[] {  });
@@ -621,7 +732,7 @@ public virtual Task<string> GetUnauthenticated()
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetAuthenticated()
+        Task<string> AuthenticatedClientHandlerTests.IMyAuthenticatedService.GetAuthenticated()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetAuthenticated", new Type[] {  });
@@ -653,7 +764,7 @@ public AutoGeneratedINamespaceCollisionApi(HttpClient client, IRequestBuilder re
         }
 
         /// <inheritdoc />
-        public virtual Task<SomeType> SomeRequest()
+        Task<SomeType> INamespaceCollisionApi.SomeRequest()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("SomeRequest", new Type[] {  });
@@ -685,7 +796,7 @@ public AutoGeneratedTestNestedINestedGitHubApi(HttpClient client, IRequestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task<User> GetUser(string userName)
+        Task<User> TestNested.INestedGitHubApi.GetUser(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUser", new Type[] { typeof(string) });
@@ -693,7 +804,7 @@ public virtual Task<User> GetUser(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserObservable(string userName)
+        IObservable<User> TestNested.INestedGitHubApi.GetUserObservable(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservable", new Type[] { typeof(string) });
@@ -701,7 +812,7 @@ public virtual IObservable<User> GetUserObservable(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserCamelCase(string userName)
+        IObservable<User> TestNested.INestedGitHubApi.GetUserCamelCase(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserCamelCase", new Type[] { typeof(string) });
@@ -709,7 +820,7 @@ public virtual IObservable<User> GetUserCamelCase(string userName)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<User>> GetOrgMembers(string orgName)
+        Task<List<User>> TestNested.INestedGitHubApi.GetOrgMembers(string orgName)
         {
             var arguments = new object[] { orgName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetOrgMembers", new Type[] { typeof(string) });
@@ -717,7 +828,7 @@ public virtual Task<List<User>> GetOrgMembers(string orgName)
         }
 
         /// <inheritdoc />
-        public virtual Task<UserSearchResult> FindUsers(string q)
+        Task<UserSearchResult> TestNested.INestedGitHubApi.FindUsers(string q)
         {
             var arguments = new object[] { q };
             var func = requestBuilder.BuildRestResultFuncForMethod("FindUsers", new Type[] { typeof(string) });
@@ -725,7 +836,7 @@ public virtual Task<UserSearchResult> FindUsers(string q)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> GetIndex()
+        Task<HttpResponseMessage> TestNested.INestedGitHubApi.GetIndex()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndex", new Type[] {  });
@@ -733,7 +844,7 @@ public virtual Task<HttpResponseMessage> GetIndex()
         }
 
         /// <inheritdoc />
-        public virtual IObservable<string> GetIndexObservable()
+        IObservable<string> TestNested.INestedGitHubApi.GetIndexObservable()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndexObservable", new Type[] {  });
@@ -741,7 +852,7 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task NothingToSeeHere()
+        Task TestNested.INestedGitHubApi.NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  });
@@ -773,9 +884,7 @@ public AutoGeneratedINonGenericInterfaceWithGenericMethod(HttpClient client, IRe
         }
 
         /// <inheritdoc />
-        public virtual Task PostMessage<T>
-            (T message)
-            where T : IMessage
+        Task INonGenericInterfaceWithGenericMethod.PostMessage<T>(T message)
         {
             var arguments = new object[] { message };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostMessage", new Type[] { typeof(T) }, new Type[] { typeof(T) });
@@ -783,9 +892,7 @@ public virtual Task PostMessage<T>
         }
 
         /// <inheritdoc />
-        public virtual Task PostMessage<T, U, V>
-            (T message,U param1,V param2)
-            where T : IMessage where U : T
+        Task INonGenericInterfaceWithGenericMethod.PostMessage<T, U, V>(T message,U param1,V param2)
         {
             var arguments = new object[] { message,param1,param2 };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostMessage", new Type[] { typeof(T),typeof(U),typeof(V) }, new Type[] { typeof(T), typeof(U), typeof(V) });
@@ -817,7 +924,7 @@ public AutoGeneratedINpmJs(HttpClient client, IRequestBuilder requestBuilder)
         }
 
         /// <inheritdoc />
-        public virtual Task<RootObject> GetCongruence()
+        Task<RootObject> INpmJs.GetCongruence()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetCongruence", new Type[] {  });
@@ -849,7 +956,7 @@ public AutoGeneratedIRequestBin(HttpClient client, IRequestBuilder requestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IRequestBin.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -857,7 +964,7 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringDefault(string str)
+        Task IRequestBin.PostRawStringDefault(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringDefault", new Type[] { typeof(string) });
@@ -865,7 +972,7 @@ public virtual Task PostRawStringDefault(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringJson(string str)
+        Task IRequestBin.PostRawStringJson(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringJson", new Type[] { typeof(string) });
@@ -873,7 +980,7 @@ public virtual Task PostRawStringJson(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringUrlEncoded(string str)
+        Task IRequestBin.PostRawStringUrlEncoded(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringUrlEncoded", new Type[] { typeof(string) });
@@ -881,8 +988,7 @@ public virtual Task PostRawStringUrlEncoded(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostGeneric<T>
-            (T param)
+        Task IRequestBin.PostGeneric<T>(T param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostGeneric", new Type[] { typeof(T) }, new Type[] { typeof(T) });
@@ -914,7 +1020,7 @@ public AutoGeneratedIRunscopeApi(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadStream(Stream stream)
+        Task<HttpResponseMessage> IRunscopeApi.UploadStream(Stream stream)
         {
             var arguments = new object[] { stream };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadStream", new Type[] { typeof(Stream) });
@@ -922,7 +1028,7 @@ public virtual Task<HttpResponseMessage> UploadStream(Stream stream)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadStreamPart(StreamPart stream)
+        Task<HttpResponseMessage> IRunscopeApi.UploadStreamPart(StreamPart stream)
         {
             var arguments = new object[] { stream };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadStreamPart", new Type[] { typeof(StreamPart) });
@@ -930,7 +1036,7 @@ public virtual Task<HttpResponseMessage> UploadStreamPart(StreamPart stream)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadBytes(byte[] bytes)
+        Task<HttpResponseMessage> IRunscopeApi.UploadBytes(byte[] bytes)
         {
             var arguments = new object[] { bytes };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadBytes", new Type[] { typeof(byte[]) });
@@ -938,7 +1044,7 @@ public virtual Task<HttpResponseMessage> UploadBytes(byte[] bytes)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadBytesPart(ByteArrayPart bytes)
+        Task<HttpResponseMessage> IRunscopeApi.UploadBytesPart(ByteArrayPart bytes)
         {
             var arguments = new object[] { bytes };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadBytesPart", new Type[] { typeof(ByteArrayPart) });
@@ -946,7 +1052,7 @@ public virtual Task<HttpResponseMessage> UploadBytesPart(ByteArrayPart bytes)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadString(string someString)
+        Task<HttpResponseMessage> IRunscopeApi.UploadString(string someString)
         {
             var arguments = new object[] { someString };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadString", new Type[] { typeof(string) });
@@ -954,7 +1060,7 @@ public virtual Task<HttpResponseMessage> UploadString(string someString)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadFileInfo(IEnumerable<FileInfo> fileInfos,FileInfo anotherFile)
+        Task<HttpResponseMessage> IRunscopeApi.UploadFileInfo(IEnumerable<FileInfo> fileInfos,FileInfo anotherFile)
         {
             var arguments = new object[] { fileInfos,anotherFile };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadFileInfo", new Type[] { typeof(IEnumerable<FileInfo>),typeof(FileInfo) });
@@ -962,7 +1068,7 @@ public virtual Task<HttpResponseMessage> UploadFileInfo(IEnumerable<FileInfo> fi
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadFileInfoPart(IEnumerable<FileInfoPart> fileInfos,FileInfoPart anotherFile)
+        Task<HttpResponseMessage> IRunscopeApi.UploadFileInfoPart(IEnumerable<FileInfoPart> fileInfos,FileInfoPart anotherFile)
         {
             var arguments = new object[] { fileInfos,anotherFile };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadFileInfoPart", new Type[] { typeof(IEnumerable<FileInfoPart>),typeof(FileInfoPart) });
@@ -970,7 +1076,7 @@ public virtual Task<HttpResponseMessage> UploadFileInfoPart(IEnumerable<FileInfo
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadJsonObject(ModelObject theObject)
+        Task<HttpResponseMessage> IRunscopeApi.UploadJsonObject(ModelObject theObject)
         {
             var arguments = new object[] { theObject };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadJsonObject", new Type[] { typeof(ModelObject) });
@@ -978,7 +1084,7 @@ public virtual Task<HttpResponseMessage> UploadJsonObject(ModelObject theObject)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadJsonObjects(IEnumerable<ModelObject> theObjects)
+        Task<HttpResponseMessage> IRunscopeApi.UploadJsonObjects(IEnumerable<ModelObject> theObjects)
         {
             var arguments = new object[] { theObjects };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadJsonObjects", new Type[] { typeof(IEnumerable<ModelObject>) });
@@ -986,7 +1092,7 @@ public virtual Task<HttpResponseMessage> UploadJsonObjects(IEnumerable<ModelObje
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadMixedObjects(IEnumerable<ModelObject> theObjects,AnotherModel anotherModel,FileInfo aFile,AnEnum anEnum,string aString,int anInt)
+        Task<HttpResponseMessage> IRunscopeApi.UploadMixedObjects(IEnumerable<ModelObject> theObjects,AnotherModel anotherModel,FileInfo aFile,AnEnum anEnum,string aString,int anInt)
         {
             var arguments = new object[] { theObjects,anotherModel,aFile,anEnum,aString,anInt };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadMixedObjects", new Type[] { typeof(IEnumerable<ModelObject>),typeof(AnotherModel),typeof(FileInfo),typeof(AnEnum),typeof(string),typeof(int) });
@@ -994,7 +1100,7 @@ public virtual Task<HttpResponseMessage> UploadMixedObjects(IEnumerable<ModelObj
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadHttpContent(HttpContent content)
+        Task<HttpResponseMessage> IRunscopeApi.UploadHttpContent(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadHttpContent", new Type[] { typeof(HttpContent) });
@@ -1026,7 +1132,7 @@ public AutoGeneratedIServiceWithoutNamespace(HttpClient client, IRequestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task GetRoot()
+        Task IServiceWithoutNamespace.GetRoot()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRoot", new Type[] {  });
@@ -1034,7 +1140,7 @@ public virtual Task GetRoot()
         }
 
         /// <inheritdoc />
-        public virtual Task PostRoot()
+        Task IServiceWithoutNamespace.PostRoot()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRoot", new Type[] {  });
@@ -1066,7 +1172,7 @@ public AutoGeneratedIStreamApi(HttpClient client, IRequestBuilder requestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task<Stream> GetRemoteFile(string filename)
+        Task<Stream> IStreamApi.GetRemoteFile(string filename)
         {
             var arguments = new object[] { filename };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRemoteFile", new Type[] { typeof(string) });
@@ -1074,7 +1180,7 @@ public virtual Task<Stream> GetRemoteFile(string filename)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<Stream>> GetRemoteFileWithMetadata(string filename)
+        Task<ApiResponse<Stream>> IStreamApi.GetRemoteFileWithMetadata(string filename)
         {
             var arguments = new object[] { filename };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRemoteFileWithMetadata", new Type[] { typeof(string) });
@@ -1106,7 +1212,7 @@ public AutoGeneratedITrimTrailingForwardSlashApi(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task ITrimTrailingForwardSlashApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1142,7 +1248,7 @@ public AutoGeneratedIUseOverloadedGenericMethods(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<string> Get()
+        Task<string> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1150,7 +1256,7 @@ public virtual Task<string> Get()
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(TParam param,THeader header)
+        Task<TResponse> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(TParam param,THeader header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TParam),typeof(THeader) });
@@ -1158,7 +1264,7 @@ public virtual Task<TResponse> Get(TParam param,THeader header)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(THeader param,TParam header)
+        Task<TResponse> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(THeader param,TParam header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(THeader),typeof(TParam) });
@@ -1166,7 +1272,7 @@ public virtual Task<TResponse> Get(THeader param,TParam header)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
+        Task<HttpResponseMessage> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(int httpstatuscode)
         {
             var arguments = new object[] { httpstatuscode };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) });
@@ -1174,8 +1280,7 @@ public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> Get<TValue>
-            (int someVal)
+        Task<TValue> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TValue>(int someVal)
         {
             var arguments = new object[] { someVal };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) }, new Type[] { typeof(TValue) });
@@ -1183,8 +1288,7 @@ public virtual Task<TValue> Get<TValue>
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> Get<TValue, TInput>
-            (TInput input)
+        Task<TValue> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TValue, TInput>(TInput input)
         {
             var arguments = new object[] { input };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TInput) }, new Type[] { typeof(TValue), typeof(TInput) });
@@ -1192,8 +1296,7 @@ public virtual Task<TValue> Get<TValue, TInput>
         }
 
         /// <inheritdoc />
-        public virtual Task Get<TInput1, TInput2>
-            (TInput1 input1,TInput2 input2)
+        Task IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TInput1, TInput2>(TInput1 input1,TInput2 input2)
         {
             var arguments = new object[] { input1,input2 };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TInput1),typeof(TInput2) }, new Type[] { typeof(TInput1), typeof(TInput2) });
@@ -1225,7 +1328,7 @@ public AutoGeneratedIUseOverloadedMethods(HttpClient client, IRequestBuilder req
         }
 
         /// <inheritdoc />
-        public virtual Task<string> Get()
+        Task<string> IUseOverloadedMethods.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1233,7 +1336,7 @@ public virtual Task<string> Get()
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
+        Task<HttpResponseMessage> IUseOverloadedMethods.Get(int httpstatuscode)
         {
             var arguments = new object[] { httpstatuscode };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) });
@@ -1265,7 +1368,7 @@ public AutoGeneratedIValidApi(HttpClient client, IRequestBuilder requestBuilder)
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IValidApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
diff --git a/Refit.Tests/RefitStubs.NetCore2.cs b/Refit.Tests/RefitStubs.NetCore2.cs
index fda73a626..f3d0ad3d3 100644
--- a/Refit.Tests/RefitStubs.NetCore2.cs
+++ b/Refit.Tests/RefitStubs.NetCore2.cs
@@ -73,7 +73,7 @@ public AutoGeneratedIAmARefitInterfaceButNobodyUsesMe(HttpClient client, IReques
         }
 
         /// <inheritdoc />
-        public virtual Task RefitMethod()
+        Task IAmARefitInterfaceButNobodyUsesMe.RefitMethod()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("RefitMethod", new Type[] {  });
@@ -81,7 +81,7 @@ public virtual Task RefitMethod()
         }
 
         /// <inheritdoc />
-        public virtual Task AnotherRefitMethod()
+        Task IAmARefitInterfaceButNobodyUsesMe.AnotherRefitMethod()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("AnotherRefitMethod", new Type[] {  });
@@ -89,13 +89,13 @@ public virtual Task AnotherRefitMethod()
         }
 
         /// <inheritdoc />
-        public virtual Task NoConstantsAllowed()
+        Task IAmARefitInterfaceButNobodyUsesMe.NoConstantsAllowed()
         {
             throw new NotImplementedException("Either this method has no Refit HTTP method attribute or you've used something other than a string literal for the 'path' argument.");
         }
 
         /// <inheritdoc />
-        public virtual Task SpacesShouldntBreakMe()
+        Task IAmARefitInterfaceButNobodyUsesMe.SpacesShouldntBreakMe()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("SpacesShouldntBreakMe", new Type[] {  });
@@ -103,7 +103,7 @@ public virtual Task SpacesShouldntBreakMe()
         }
 
         /// <inheritdoc />
-        public virtual Task ReservedWordsForParameterNames(int @int,string @string,float @long)
+        Task IAmARefitInterfaceButNobodyUsesMe.ReservedWordsForParameterNames(int @int,string @string,float @long)
         {
             var arguments = new object[] { @int,@string,@long };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReservedWordsForParameterNames", new Type[] { typeof(int),typeof(string),typeof(float) });
@@ -135,7 +135,7 @@ public AutoGeneratedIAmHalfRefit(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IAmHalfRefit.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -143,13 +143,125 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IAmHalfRefit.Get()
         {
             throw new NotImplementedException("Either this method has no Refit HTTP method attribute or you've used something other than a string literal for the 'path' argument.");
         }
     }
 }
 
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceA : IAmInterfaceA
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceA(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceA.Ping()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Ping", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceB : IAmInterfaceB
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceB(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceB.Pong()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pong", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
+namespace Refit.Tests
+{
+    using Refit.Tests.RefitInternalGenerated;
+
+    /// <inheritdoc />
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    [global::System.Diagnostics.DebuggerNonUserCode]
+    [Preserve]
+    [global::System.Reflection.Obfuscation(Exclude=true)]
+    partial class AutoGeneratedIAmInterfaceC : IAmInterfaceC
+    {
+        /// <inheritdoc />
+        public HttpClient Client { get; protected set; }
+        readonly IRequestBuilder requestBuilder;
+
+        /// <inheritdoc />
+        public AutoGeneratedIAmInterfaceC(HttpClient client, IRequestBuilder requestBuilder)
+        {
+            Client = client;
+            this.requestBuilder = requestBuilder;
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceC.Pang()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pang", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceA.Ping()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Ping", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+
+        /// <inheritdoc />
+        Task<string> IAmInterfaceB.Pong()
+        {
+            var arguments = new object[] {  };
+            var func = requestBuilder.BuildRestResultFuncForMethod("Pong", new Type[] {  });
+            return (Task<string>)func(Client, arguments);
+        }
+    }
+}
+
 namespace Refit.Tests
 {
     using Refit.Tests.RefitInternalGenerated;
@@ -173,7 +285,7 @@ public AutoGeneratedIApiWithDecimal(HttpClient client, IRequestBuilder requestBu
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetWithDecimal(decimal value)
+        Task<string> IApiWithDecimal.GetWithDecimal(decimal value)
         {
             var arguments = new object[] { value };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetWithDecimal", new Type[] { typeof(decimal) });
@@ -205,7 +317,7 @@ public AutoGeneratedIBodylessApi(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IBodylessApi.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -213,7 +325,7 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IBodylessApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -221,7 +333,7 @@ public virtual Task Get()
         }
 
         /// <inheritdoc />
-        public virtual Task Head()
+        Task IBodylessApi.Head()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Head", new Type[] {  });
@@ -256,7 +368,7 @@ public AutoGeneratedIBoringCrudApi(HttpClient client, IRequestBuilder requestBui
         }
 
         /// <inheritdoc />
-        public virtual Task<T> Create(T paylod)
+        Task<T> IBoringCrudApi<T, TKey>.Create(T paylod)
         {
             var arguments = new object[] { paylod };
             var func = requestBuilder.BuildRestResultFuncForMethod("Create", new Type[] { typeof(T) });
@@ -264,7 +376,7 @@ public virtual Task<T> Create(T paylod)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<T>> ReadAll()
+        Task<List<T>> IBoringCrudApi<T, TKey>.ReadAll()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReadAll", new Type[] {  });
@@ -272,7 +384,7 @@ public virtual Task<List<T>> ReadAll()
         }
 
         /// <inheritdoc />
-        public virtual Task<T> ReadOne(TKey key)
+        Task<T> IBoringCrudApi<T, TKey>.ReadOne(TKey key)
         {
             var arguments = new object[] { key };
             var func = requestBuilder.BuildRestResultFuncForMethod("ReadOne", new Type[] { typeof(TKey) });
@@ -280,7 +392,7 @@ public virtual Task<T> ReadOne(TKey key)
         }
 
         /// <inheritdoc />
-        public virtual Task Update(TKey key,T payload)
+        Task IBoringCrudApi<T, TKey>.Update(TKey key,T payload)
         {
             var arguments = new object[] { key,payload };
             var func = requestBuilder.BuildRestResultFuncForMethod("Update", new Type[] { typeof(TKey),typeof(T) });
@@ -288,7 +400,7 @@ public virtual Task Update(TKey key,T payload)
         }
 
         /// <inheritdoc />
-        public virtual Task Delete(TKey key)
+        Task IBoringCrudApi<T, TKey>.Delete(TKey key)
         {
             var arguments = new object[] { key };
             var func = requestBuilder.BuildRestResultFuncForMethod("Delete", new Type[] { typeof(TKey) });
@@ -320,7 +432,7 @@ public AutoGeneratedIBrokenWebApi(HttpClient client, IRequestBuilder requestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<bool> PostAValue(string derp)
+        Task<bool> IBrokenWebApi.PostAValue(string derp)
         {
             var arguments = new object[] { derp };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostAValue", new Type[] { typeof(string) });
@@ -352,7 +464,7 @@ public AutoGeneratedIGitHubApi(HttpClient client, IRequestBuilder requestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task<User> GetUser(string userName)
+        Task<User> IGitHubApi.GetUser(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUser", new Type[] { typeof(string) });
@@ -360,7 +472,7 @@ public virtual Task<User> GetUser(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserObservable(string userName)
+        IObservable<User> IGitHubApi.GetUserObservable(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservable", new Type[] { typeof(string) });
@@ -368,7 +480,7 @@ public virtual IObservable<User> GetUserObservable(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserCamelCase(string userName)
+        IObservable<User> IGitHubApi.GetUserCamelCase(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserCamelCase", new Type[] { typeof(string) });
@@ -376,7 +488,7 @@ public virtual IObservable<User> GetUserCamelCase(string userName)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<User>> GetOrgMembers(string orgName)
+        Task<List<User>> IGitHubApi.GetOrgMembers(string orgName)
         {
             var arguments = new object[] { orgName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetOrgMembers", new Type[] { typeof(string) });
@@ -384,7 +496,7 @@ public virtual Task<List<User>> GetOrgMembers(string orgName)
         }
 
         /// <inheritdoc />
-        public virtual Task<UserSearchResult> FindUsers(string q)
+        Task<UserSearchResult> IGitHubApi.FindUsers(string q)
         {
             var arguments = new object[] { q };
             var func = requestBuilder.BuildRestResultFuncForMethod("FindUsers", new Type[] { typeof(string) });
@@ -392,7 +504,7 @@ public virtual Task<UserSearchResult> FindUsers(string q)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> GetIndex()
+        Task<HttpResponseMessage> IGitHubApi.GetIndex()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndex", new Type[] {  });
@@ -400,7 +512,7 @@ public virtual Task<HttpResponseMessage> GetIndex()
         }
 
         /// <inheritdoc />
-        public virtual IObservable<string> GetIndexObservable()
+        IObservable<string> IGitHubApi.GetIndexObservable()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndexObservable", new Type[] {  });
@@ -408,7 +520,7 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task<User> NothingToSeeHere()
+        Task<User> IGitHubApi.NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  });
@@ -416,7 +528,7 @@ public virtual Task<User> NothingToSeeHere()
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
+        Task<ApiResponse<User>> IGitHubApi.NothingToSeeHereWithMetadata()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHereWithMetadata", new Type[] {  });
@@ -424,7 +536,7 @@ public virtual Task<ApiResponse<User>> NothingToSeeHereWithMetadata()
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> GetUserWithMetadata(string userName)
+        Task<ApiResponse<User>> IGitHubApi.GetUserWithMetadata(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserWithMetadata", new Type[] { typeof(string) });
@@ -432,7 +544,7 @@ public virtual Task<ApiResponse<User>> GetUserWithMetadata(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<ApiResponse<User>> GetUserObservableWithMetadata(string userName)
+        IObservable<ApiResponse<User>> IGitHubApi.GetUserObservableWithMetadata(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservableWithMetadata", new Type[] { typeof(string) });
@@ -440,7 +552,7 @@ public virtual IObservable<ApiResponse<User>> GetUserObservableWithMetadata(stri
         }
 
         /// <inheritdoc />
-        public virtual Task<User> CreateUser(User user)
+        Task<User> IGitHubApi.CreateUser(User user)
         {
             var arguments = new object[] { user };
             var func = requestBuilder.BuildRestResultFuncForMethod("CreateUser", new Type[] { typeof(User) });
@@ -448,7 +560,7 @@ public virtual Task<User> CreateUser(User user)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<User>> CreateUserWithMetadata(User user)
+        Task<ApiResponse<User>> IGitHubApi.CreateUserWithMetadata(User user)
         {
             var arguments = new object[] { user };
             var func = requestBuilder.BuildRestResultFuncForMethod("CreateUserWithMetadata", new Type[] { typeof(User) });
@@ -484,7 +596,7 @@ public AutoGeneratedIHttpBinApi(HttpClient client, IRequestBuilder requestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(TParam param,THeader header)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.Get(TParam param,THeader header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TParam),typeof(THeader) });
@@ -492,7 +604,7 @@ public virtual Task<TResponse> Get(TParam param,THeader header)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> GetQuery(TParam param)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.GetQuery(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQuery", new Type[] { typeof(TParam) });
@@ -500,7 +612,7 @@ public virtual Task<TResponse> GetQuery(TParam param)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> GetQueryWithIncludeParameterName(TParam param)
+        Task<TResponse> IHttpBinApi<TResponse, TParam, THeader>.GetQueryWithIncludeParameterName(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQueryWithIncludeParameterName", new Type[] { typeof(TParam) });
@@ -508,8 +620,7 @@ public virtual Task<TResponse> GetQueryWithIncludeParameterName(TParam param)
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> GetQuery1<TValue>
-            (TParam param)
+        Task<TValue> IHttpBinApi<TResponse, TParam, THeader>.GetQuery1<TValue>(TParam param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetQuery1", new Type[] { typeof(TParam) }, new Type[] { typeof(TValue) });
@@ -541,7 +652,7 @@ public AutoGeneratedIHttpContentApi(HttpClient client, IRequestBuilder requestBu
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpContent> PostFileUpload(HttpContent content)
+        Task<HttpContent> IHttpContentApi.PostFileUpload(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostFileUpload", new Type[] { typeof(HttpContent) });
@@ -549,7 +660,7 @@ public virtual Task<HttpContent> PostFileUpload(HttpContent content)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<HttpContent>> PostFileUploadWithMetadata(HttpContent content)
+        Task<ApiResponse<HttpContent>> IHttpContentApi.PostFileUploadWithMetadata(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostFileUploadWithMetadata", new Type[] { typeof(HttpContent) });
@@ -581,7 +692,7 @@ public AutoGeneratedResponseTestsIMyAliasService(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<TestAliasObject> GetTestObject()
+        Task<TestAliasObject> ResponseTests.IMyAliasService.GetTestObject()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetTestObject", new Type[] {  });
@@ -613,7 +724,7 @@ public AutoGeneratedAuthenticatedClientHandlerTestsIMyAuthenticatedService(HttpC
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetUnauthenticated()
+        Task<string> AuthenticatedClientHandlerTests.IMyAuthenticatedService.GetUnauthenticated()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUnauthenticated", new Type[] {  });
@@ -621,7 +732,7 @@ public virtual Task<string> GetUnauthenticated()
         }
 
         /// <inheritdoc />
-        public virtual Task<string> GetAuthenticated()
+        Task<string> AuthenticatedClientHandlerTests.IMyAuthenticatedService.GetAuthenticated()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetAuthenticated", new Type[] {  });
@@ -653,7 +764,7 @@ public AutoGeneratedINamespaceCollisionApi(HttpClient client, IRequestBuilder re
         }
 
         /// <inheritdoc />
-        public virtual Task<SomeType> SomeRequest()
+        Task<SomeType> INamespaceCollisionApi.SomeRequest()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("SomeRequest", new Type[] {  });
@@ -685,7 +796,7 @@ public AutoGeneratedTestNestedINestedGitHubApi(HttpClient client, IRequestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task<User> GetUser(string userName)
+        Task<User> TestNested.INestedGitHubApi.GetUser(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUser", new Type[] { typeof(string) });
@@ -693,7 +804,7 @@ public virtual Task<User> GetUser(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserObservable(string userName)
+        IObservable<User> TestNested.INestedGitHubApi.GetUserObservable(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserObservable", new Type[] { typeof(string) });
@@ -701,7 +812,7 @@ public virtual IObservable<User> GetUserObservable(string userName)
         }
 
         /// <inheritdoc />
-        public virtual IObservable<User> GetUserCamelCase(string userName)
+        IObservable<User> TestNested.INestedGitHubApi.GetUserCamelCase(string userName)
         {
             var arguments = new object[] { userName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetUserCamelCase", new Type[] { typeof(string) });
@@ -709,7 +820,7 @@ public virtual IObservable<User> GetUserCamelCase(string userName)
         }
 
         /// <inheritdoc />
-        public virtual Task<List<User>> GetOrgMembers(string orgName)
+        Task<List<User>> TestNested.INestedGitHubApi.GetOrgMembers(string orgName)
         {
             var arguments = new object[] { orgName };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetOrgMembers", new Type[] { typeof(string) });
@@ -717,7 +828,7 @@ public virtual Task<List<User>> GetOrgMembers(string orgName)
         }
 
         /// <inheritdoc />
-        public virtual Task<UserSearchResult> FindUsers(string q)
+        Task<UserSearchResult> TestNested.INestedGitHubApi.FindUsers(string q)
         {
             var arguments = new object[] { q };
             var func = requestBuilder.BuildRestResultFuncForMethod("FindUsers", new Type[] { typeof(string) });
@@ -725,7 +836,7 @@ public virtual Task<UserSearchResult> FindUsers(string q)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> GetIndex()
+        Task<HttpResponseMessage> TestNested.INestedGitHubApi.GetIndex()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndex", new Type[] {  });
@@ -733,7 +844,7 @@ public virtual Task<HttpResponseMessage> GetIndex()
         }
 
         /// <inheritdoc />
-        public virtual IObservable<string> GetIndexObservable()
+        IObservable<string> TestNested.INestedGitHubApi.GetIndexObservable()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetIndexObservable", new Type[] {  });
@@ -741,7 +852,7 @@ public virtual IObservable<string> GetIndexObservable()
         }
 
         /// <inheritdoc />
-        public virtual Task NothingToSeeHere()
+        Task TestNested.INestedGitHubApi.NothingToSeeHere()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("NothingToSeeHere", new Type[] {  });
@@ -773,9 +884,7 @@ public AutoGeneratedINonGenericInterfaceWithGenericMethod(HttpClient client, IRe
         }
 
         /// <inheritdoc />
-        public virtual Task PostMessage<T>
-            (T message)
-            where T : IMessage
+        Task INonGenericInterfaceWithGenericMethod.PostMessage<T>(T message)
         {
             var arguments = new object[] { message };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostMessage", new Type[] { typeof(T) }, new Type[] { typeof(T) });
@@ -783,9 +892,7 @@ public virtual Task PostMessage<T>
         }
 
         /// <inheritdoc />
-        public virtual Task PostMessage<T, U, V>
-            (T message,U param1,V param2)
-            where T : IMessage where U : T
+        Task INonGenericInterfaceWithGenericMethod.PostMessage<T, U, V>(T message,U param1,V param2)
         {
             var arguments = new object[] { message,param1,param2 };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostMessage", new Type[] { typeof(T),typeof(U),typeof(V) }, new Type[] { typeof(T), typeof(U), typeof(V) });
@@ -817,7 +924,7 @@ public AutoGeneratedINpmJs(HttpClient client, IRequestBuilder requestBuilder)
         }
 
         /// <inheritdoc />
-        public virtual Task<RootObject> GetCongruence()
+        Task<RootObject> INpmJs.GetCongruence()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetCongruence", new Type[] {  });
@@ -849,7 +956,7 @@ public AutoGeneratedIRequestBin(HttpClient client, IRequestBuilder requestBuilde
         }
 
         /// <inheritdoc />
-        public virtual Task Post()
+        Task IRequestBin.Post()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Post", new Type[] {  });
@@ -857,7 +964,7 @@ public virtual Task Post()
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringDefault(string str)
+        Task IRequestBin.PostRawStringDefault(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringDefault", new Type[] { typeof(string) });
@@ -865,7 +972,7 @@ public virtual Task PostRawStringDefault(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringJson(string str)
+        Task IRequestBin.PostRawStringJson(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringJson", new Type[] { typeof(string) });
@@ -873,7 +980,7 @@ public virtual Task PostRawStringJson(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostRawStringUrlEncoded(string str)
+        Task IRequestBin.PostRawStringUrlEncoded(string str)
         {
             var arguments = new object[] { str };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRawStringUrlEncoded", new Type[] { typeof(string) });
@@ -881,8 +988,7 @@ public virtual Task PostRawStringUrlEncoded(string str)
         }
 
         /// <inheritdoc />
-        public virtual Task PostGeneric<T>
-            (T param)
+        Task IRequestBin.PostGeneric<T>(T param)
         {
             var arguments = new object[] { param };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostGeneric", new Type[] { typeof(T) }, new Type[] { typeof(T) });
@@ -914,7 +1020,7 @@ public AutoGeneratedIRunscopeApi(HttpClient client, IRequestBuilder requestBuild
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadStream(Stream stream)
+        Task<HttpResponseMessage> IRunscopeApi.UploadStream(Stream stream)
         {
             var arguments = new object[] { stream };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadStream", new Type[] { typeof(Stream) });
@@ -922,7 +1028,7 @@ public virtual Task<HttpResponseMessage> UploadStream(Stream stream)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadStreamPart(StreamPart stream)
+        Task<HttpResponseMessage> IRunscopeApi.UploadStreamPart(StreamPart stream)
         {
             var arguments = new object[] { stream };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadStreamPart", new Type[] { typeof(StreamPart) });
@@ -930,7 +1036,7 @@ public virtual Task<HttpResponseMessage> UploadStreamPart(StreamPart stream)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadBytes(byte[] bytes)
+        Task<HttpResponseMessage> IRunscopeApi.UploadBytes(byte[] bytes)
         {
             var arguments = new object[] { bytes };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadBytes", new Type[] { typeof(byte[]) });
@@ -938,7 +1044,7 @@ public virtual Task<HttpResponseMessage> UploadBytes(byte[] bytes)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadBytesPart(ByteArrayPart bytes)
+        Task<HttpResponseMessage> IRunscopeApi.UploadBytesPart(ByteArrayPart bytes)
         {
             var arguments = new object[] { bytes };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadBytesPart", new Type[] { typeof(ByteArrayPart) });
@@ -946,7 +1052,7 @@ public virtual Task<HttpResponseMessage> UploadBytesPart(ByteArrayPart bytes)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadString(string someString)
+        Task<HttpResponseMessage> IRunscopeApi.UploadString(string someString)
         {
             var arguments = new object[] { someString };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadString", new Type[] { typeof(string) });
@@ -954,7 +1060,7 @@ public virtual Task<HttpResponseMessage> UploadString(string someString)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadFileInfo(IEnumerable<FileInfo> fileInfos,FileInfo anotherFile)
+        Task<HttpResponseMessage> IRunscopeApi.UploadFileInfo(IEnumerable<FileInfo> fileInfos,FileInfo anotherFile)
         {
             var arguments = new object[] { fileInfos,anotherFile };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadFileInfo", new Type[] { typeof(IEnumerable<FileInfo>),typeof(FileInfo) });
@@ -962,7 +1068,7 @@ public virtual Task<HttpResponseMessage> UploadFileInfo(IEnumerable<FileInfo> fi
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadFileInfoPart(IEnumerable<FileInfoPart> fileInfos,FileInfoPart anotherFile)
+        Task<HttpResponseMessage> IRunscopeApi.UploadFileInfoPart(IEnumerable<FileInfoPart> fileInfos,FileInfoPart anotherFile)
         {
             var arguments = new object[] { fileInfos,anotherFile };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadFileInfoPart", new Type[] { typeof(IEnumerable<FileInfoPart>),typeof(FileInfoPart) });
@@ -970,7 +1076,7 @@ public virtual Task<HttpResponseMessage> UploadFileInfoPart(IEnumerable<FileInfo
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadJsonObject(ModelObject theObject)
+        Task<HttpResponseMessage> IRunscopeApi.UploadJsonObject(ModelObject theObject)
         {
             var arguments = new object[] { theObject };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadJsonObject", new Type[] { typeof(ModelObject) });
@@ -978,7 +1084,7 @@ public virtual Task<HttpResponseMessage> UploadJsonObject(ModelObject theObject)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadJsonObjects(IEnumerable<ModelObject> theObjects)
+        Task<HttpResponseMessage> IRunscopeApi.UploadJsonObjects(IEnumerable<ModelObject> theObjects)
         {
             var arguments = new object[] { theObjects };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadJsonObjects", new Type[] { typeof(IEnumerable<ModelObject>) });
@@ -986,7 +1092,7 @@ public virtual Task<HttpResponseMessage> UploadJsonObjects(IEnumerable<ModelObje
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadMixedObjects(IEnumerable<ModelObject> theObjects,AnotherModel anotherModel,FileInfo aFile,AnEnum anEnum,string aString,int anInt)
+        Task<HttpResponseMessage> IRunscopeApi.UploadMixedObjects(IEnumerable<ModelObject> theObjects,AnotherModel anotherModel,FileInfo aFile,AnEnum anEnum,string aString,int anInt)
         {
             var arguments = new object[] { theObjects,anotherModel,aFile,anEnum,aString,anInt };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadMixedObjects", new Type[] { typeof(IEnumerable<ModelObject>),typeof(AnotherModel),typeof(FileInfo),typeof(AnEnum),typeof(string),typeof(int) });
@@ -994,7 +1100,7 @@ public virtual Task<HttpResponseMessage> UploadMixedObjects(IEnumerable<ModelObj
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> UploadHttpContent(HttpContent content)
+        Task<HttpResponseMessage> IRunscopeApi.UploadHttpContent(HttpContent content)
         {
             var arguments = new object[] { content };
             var func = requestBuilder.BuildRestResultFuncForMethod("UploadHttpContent", new Type[] { typeof(HttpContent) });
@@ -1026,7 +1132,7 @@ public AutoGeneratedIServiceWithoutNamespace(HttpClient client, IRequestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task GetRoot()
+        Task IServiceWithoutNamespace.GetRoot()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRoot", new Type[] {  });
@@ -1034,7 +1140,7 @@ public virtual Task GetRoot()
         }
 
         /// <inheritdoc />
-        public virtual Task PostRoot()
+        Task IServiceWithoutNamespace.PostRoot()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("PostRoot", new Type[] {  });
@@ -1066,7 +1172,7 @@ public AutoGeneratedIStreamApi(HttpClient client, IRequestBuilder requestBuilder
         }
 
         /// <inheritdoc />
-        public virtual Task<Stream> GetRemoteFile(string filename)
+        Task<Stream> IStreamApi.GetRemoteFile(string filename)
         {
             var arguments = new object[] { filename };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRemoteFile", new Type[] { typeof(string) });
@@ -1074,7 +1180,7 @@ public virtual Task<Stream> GetRemoteFile(string filename)
         }
 
         /// <inheritdoc />
-        public virtual Task<ApiResponse<Stream>> GetRemoteFileWithMetadata(string filename)
+        Task<ApiResponse<Stream>> IStreamApi.GetRemoteFileWithMetadata(string filename)
         {
             var arguments = new object[] { filename };
             var func = requestBuilder.BuildRestResultFuncForMethod("GetRemoteFileWithMetadata", new Type[] { typeof(string) });
@@ -1106,7 +1212,7 @@ public AutoGeneratedITrimTrailingForwardSlashApi(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task ITrimTrailingForwardSlashApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1142,7 +1248,7 @@ public AutoGeneratedIUseOverloadedGenericMethods(HttpClient client, IRequestBuil
         }
 
         /// <inheritdoc />
-        public virtual Task<string> Get()
+        Task<string> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1150,7 +1256,7 @@ public virtual Task<string> Get()
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(TParam param,THeader header)
+        Task<TResponse> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(TParam param,THeader header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TParam),typeof(THeader) });
@@ -1158,7 +1264,7 @@ public virtual Task<TResponse> Get(TParam param,THeader header)
         }
 
         /// <inheritdoc />
-        public virtual Task<TResponse> Get(THeader param,TParam header)
+        Task<TResponse> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(THeader param,TParam header)
         {
             var arguments = new object[] { param,header };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(THeader),typeof(TParam) });
@@ -1166,7 +1272,7 @@ public virtual Task<TResponse> Get(THeader param,TParam header)
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
+        Task<HttpResponseMessage> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get(int httpstatuscode)
         {
             var arguments = new object[] { httpstatuscode };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) });
@@ -1174,8 +1280,7 @@ public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> Get<TValue>
-            (int someVal)
+        Task<TValue> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TValue>(int someVal)
         {
             var arguments = new object[] { someVal };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) }, new Type[] { typeof(TValue) });
@@ -1183,8 +1288,7 @@ public virtual Task<TValue> Get<TValue>
         }
 
         /// <inheritdoc />
-        public virtual Task<TValue> Get<TValue, TInput>
-            (TInput input)
+        Task<TValue> IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TValue, TInput>(TInput input)
         {
             var arguments = new object[] { input };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TInput) }, new Type[] { typeof(TValue), typeof(TInput) });
@@ -1192,8 +1296,7 @@ public virtual Task<TValue> Get<TValue, TInput>
         }
 
         /// <inheritdoc />
-        public virtual Task Get<TInput1, TInput2>
-            (TInput1 input1,TInput2 input2)
+        Task IUseOverloadedGenericMethods<TResponse, TParam, THeader>.Get<TInput1, TInput2>(TInput1 input1,TInput2 input2)
         {
             var arguments = new object[] { input1,input2 };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(TInput1),typeof(TInput2) }, new Type[] { typeof(TInput1), typeof(TInput2) });
@@ -1225,7 +1328,7 @@ public AutoGeneratedIUseOverloadedMethods(HttpClient client, IRequestBuilder req
         }
 
         /// <inheritdoc />
-        public virtual Task<string> Get()
+        Task<string> IUseOverloadedMethods.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
@@ -1233,7 +1336,7 @@ public virtual Task<string> Get()
         }
 
         /// <inheritdoc />
-        public virtual Task<HttpResponseMessage> Get(int httpstatuscode)
+        Task<HttpResponseMessage> IUseOverloadedMethods.Get(int httpstatuscode)
         {
             var arguments = new object[] { httpstatuscode };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] { typeof(int) });
@@ -1265,7 +1368,7 @@ public AutoGeneratedIValidApi(HttpClient client, IRequestBuilder requestBuilder)
         }
 
         /// <inheritdoc />
-        public virtual Task Get()
+        Task IValidApi.Get()
         {
             var arguments = new object[] {  };
             var func = requestBuilder.BuildRestResultFuncForMethod("Get", new Type[] {  });
diff --git a/Refit.Tests/RestService.cs b/Refit.Tests/RestService.cs
index 710f8a250..ab8da5111 100644
--- a/Refit.Tests/RestService.cs
+++ b/Refit.Tests/RestService.cs
@@ -1069,6 +1069,36 @@ public async Task GenericMethodTest()
             mockHttp.VerifyNoOutstandingExpectation();
         }
 
+        [Fact]
+        public async Task InheritedMethodTest()
+        {
+            var mockHttp = new MockHttpMessageHandler();
+
+            var settings = new RefitSettings
+            {
+                HttpMessageHandlerFactory = () => mockHttp
+            };
+
+            var fixture = RestService.For<IAmInterfaceC>("https://httpbin.org", settings);
+
+            mockHttp.Expect(HttpMethod.Get, "https://httpbin.org/get").Respond("application/json", nameof(IAmInterfaceA.Ping));
+            var resp = await fixture.Ping();
+            Assert.Equal(nameof(IAmInterfaceA.Ping), resp);
+            mockHttp.VerifyNoOutstandingExpectation();
+
+            mockHttp.Expect(HttpMethod.Get, "https://httpbin.org/get")
+                .Respond("application/json", nameof(IAmInterfaceB.Pong));
+            resp = await fixture.Pong();
+            Assert.Equal(nameof(IAmInterfaceB.Pong), resp);
+            mockHttp.VerifyNoOutstandingExpectation();
+
+            mockHttp.Expect(HttpMethod.Get, "https://httpbin.org/get")
+                .Respond("application/json", nameof(IAmInterfaceC.Pang));
+            resp = await fixture.Pang();
+            Assert.Equal(nameof(IAmInterfaceC.Pang), resp);
+            mockHttp.VerifyNoOutstandingExpectation();
+        }
+
         [Fact]
         public async Task DictionaryDynamicQueryparametersTest()
         {
diff --git a/Refit/RequestBuilderImplementation.cs b/Refit/RequestBuilderImplementation.cs
index 1e96d9650..3615e2b9e 100644
--- a/Refit/RequestBuilderImplementation.cs
+++ b/Refit/RequestBuilderImplementation.cs
@@ -31,6 +31,7 @@ partial class RequestBuilderImplementation<TApi> : IRequestBuilder<TApi>
         public RequestBuilderImplementation(RefitSettings refitSettings = null)
         {
             Type targetInterface = typeof(TApi);
+            Type[] targetInterfaceInheritedInterfaces = targetInterface.GetInterfaces();
 
             settings = refitSettings ?? new RefitSettings();
             serializer = settings.ContentSerializer;
@@ -42,24 +43,35 @@ public RequestBuilderImplementation(RefitSettings refitSettings = null)
             }
 
             TargetType = targetInterface;
+
             var dict = new Dictionary<string, List<RestMethodInfo>>();
 
-            foreach (var methodInfo in targetInterface.GetMethods())
+            AddInterfaceHttpMethods(targetInterface, dict);
+            foreach (var inheritedInterface in targetInterfaceInheritedInterfaces)
+            {
+                AddInterfaceHttpMethods(inheritedInterface, dict);
+            }
+
+            interfaceHttpMethods = dict;
+        }
+
+        private void AddInterfaceHttpMethods(Type interfaceType, Dictionary<string, List<RestMethodInfo>> methods)
+        {
+            foreach (var methodInfo in interfaceType.GetMethods())
             {
                 var attrs = methodInfo.GetCustomAttributes(true);
                 var hasHttpMethod = attrs.OfType<HttpMethodAttribute>().Any();
                 if (hasHttpMethod)
                 {
-                    if (!dict.ContainsKey(methodInfo.Name))
+                    if (!methods.ContainsKey(methodInfo.Name))
                     {
-                        dict.Add(methodInfo.Name, new List<RestMethodInfo>());
+                        methods.Add(methodInfo.Name, new List<RestMethodInfo>());
                     }
-                    var restinfo = new RestMethodInfo(targetInterface, methodInfo, settings);
-                    dict[methodInfo.Name].Add(restinfo);
+
+                    var restinfo = new RestMethodInfo(interfaceType, methodInfo, settings);
+                    methods[methodInfo.Name].Add(restinfo);
                 }
             }
-
-            interfaceHttpMethods = dict;
         }
 
         RestMethodInfo FindMatchingRestMethodInfo(string key, Type[] parameterTypes, Type[] genericArgumentTypes)
diff --git a/Refit/RestMethodInfo.cs b/Refit/RestMethodInfo.cs
index 16903b2a9..429d084da 100644
--- a/Refit/RestMethodInfo.cs
+++ b/Refit/RestMethodInfo.cs
@@ -242,6 +242,10 @@ Dictionary<string, string> ParseHeaders(MethodInfo methodInfo)
         {
             var ret = new Dictionary<string, string>();
 
+            var inheritedAttributes = methodInfo.DeclaringType != null
+                ? methodInfo.DeclaringType.GetInterfaces().SelectMany(i => i.GetTypeInfo().GetCustomAttributes(true)).Reverse()
+                : new Attribute[0];
+
             var declaringTypeAttributes = methodInfo.DeclaringType != null
                 ? methodInfo.DeclaringType.GetTypeInfo().GetCustomAttributes(true)
                 : new Attribute[0];
@@ -249,7 +253,7 @@ Dictionary<string, string> ParseHeaders(MethodInfo methodInfo)
             // Headers set on the declaring type have to come first, 
             // so headers set on the method can replace them. Switching
             // the order here will break stuff.
-            var headers = declaringTypeAttributes.Concat(methodInfo.GetCustomAttributes(true))
+            var headers = inheritedAttributes.Concat(declaringTypeAttributes).Concat(methodInfo.GetCustomAttributes(true))
                 .OfType<HeadersAttribute>()
                 .SelectMany(ha => ha.Headers);