diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index ab9b287c..62016434 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -36,8 +36,9 @@ Note that genqlient is now tested from Go 1.20 through Go 1.22.
 ### Bug fixes:
 - The presence of negative pointer directives, i.e., `# @genqlient(pointer: false)` are now respected even in the when `optional: pointer` is set in the configuration file.
 - Made name collisions between query/mutation arguments and local function variables less likely.
-- Fix generation issue related to golang type implementation of complex graphql union fragments
+- Fix generation issue related to golang type implementation of complex graphql union fragments.
 - Bind correctly to types in the same package as the generated code.
+- Fix non-deterministic generated code when querying graphql interfaces via named fragments.
 
 ## v0.6.0
 
diff --git a/generate/convert.go b/generate/convert.go
index b7e6a6d2..3e3dc03f 100644
--- a/generate/convert.go
+++ b/generate/convert.go
@@ -841,6 +841,8 @@ func (g *generator) convertNamedFragment(fragment *ast.FragmentDefinition) (goTy
 		return goType, nil
 	case ast.Interface, ast.Union:
 		implementationTypes := g.schema.GetPossibleTypes(typ)
+		// Make sure we generate stable output by sorting the types by name when we get them
+		sort.Slice(implementationTypes, func(i, j int) bool { return implementationTypes[i].Name < implementationTypes[j].Name })
 		goType := &goInterfaceType{
 			GoName:          fragment.Name,
 			SharedFields:    fields,
diff --git a/generate/testdata/snapshots/TestGenerate-ComplexNamedFragments.graphql-ComplexNamedFragments.graphql.go b/generate/testdata/snapshots/TestGenerate-ComplexNamedFragments.graphql-ComplexNamedFragments.graphql.go
index 7888b2e8..b7fa016d 100644
--- a/generate/testdata/snapshots/TestGenerate-ComplexNamedFragments.graphql-ComplexNamedFragments.graphql.go
+++ b/generate/testdata/snapshots/TestGenerate-ComplexNamedFragments.graphql-ComplexNamedFragments.graphql.go
@@ -273,8 +273,8 @@ func (v *ComplexNamedFragmentsWithInlineUnionUser) __premarshalJSON() (*__premar
 //
 // ContentFields is implemented by the following types:
 // ContentFieldsArticle
-// ContentFieldsVideo
 // ContentFieldsTopic
+// ContentFieldsVideo
 type ContentFields interface {
 	implementsGraphQLInterfaceContentFields()
 	// GetName returns the interface-field "name" from its implementation.
@@ -284,8 +284,8 @@ type ContentFields interface {
 }
 
 func (v *ContentFieldsArticle) implementsGraphQLInterfaceContentFields() {}
-func (v *ContentFieldsVideo) implementsGraphQLInterfaceContentFields()   {}
 func (v *ContentFieldsTopic) implementsGraphQLInterfaceContentFields()   {}
+func (v *ContentFieldsVideo) implementsGraphQLInterfaceContentFields()   {}
 
 func __unmarshalContentFields(b []byte, v *ContentFields) error {
 	if string(b) == "null" {
@@ -304,12 +304,12 @@ func __unmarshalContentFields(b []byte, v *ContentFields) error {
 	case "Article":
 		*v = new(ContentFieldsArticle)
 		return json.Unmarshal(b, *v)
-	case "Video":
-		*v = new(ContentFieldsVideo)
-		return json.Unmarshal(b, *v)
 	case "Topic":
 		*v = new(ContentFieldsTopic)
 		return json.Unmarshal(b, *v)
+	case "Video":
+		*v = new(ContentFieldsVideo)
+		return json.Unmarshal(b, *v)
 	case "":
 		return fmt.Errorf(
 			"response was missing Content.__typename")
@@ -331,20 +331,20 @@ func __marshalContentFields(v *ContentFields) ([]byte, error) {
 			*ContentFieldsArticle
 		}{typename, v}
 		return json.Marshal(result)
-	case *ContentFieldsVideo:
-		typename = "Video"
+	case *ContentFieldsTopic:
+		typename = "Topic"
 
 		result := struct {
 			TypeName string `json:"__typename"`
-			*ContentFieldsVideo
+			*ContentFieldsTopic
 		}{typename, v}
 		return json.Marshal(result)
-	case *ContentFieldsTopic:
-		typename = "Topic"
+	case *ContentFieldsVideo:
+		typename = "Video"
 
 		result := struct {
 			TypeName string `json:"__typename"`
-			*ContentFieldsTopic
+			*ContentFieldsVideo
 		}{typename, v}
 		return json.Marshal(result)
 	case nil:
diff --git a/generate/testdata/snapshots/TestGenerate-Flatten.graphql-Flatten.graphql.go b/generate/testdata/snapshots/TestGenerate-Flatten.graphql-Flatten.graphql.go
index c05e913d..76499bc7 100644
--- a/generate/testdata/snapshots/TestGenerate-Flatten.graphql-Flatten.graphql.go
+++ b/generate/testdata/snapshots/TestGenerate-Flatten.graphql-Flatten.graphql.go
@@ -30,8 +30,8 @@ func (v *ChildVideoFields) GetName() string { return v.Name }
 //
 // ContentFields is implemented by the following types:
 // ContentFieldsArticle
-// ContentFieldsVideo
 // ContentFieldsTopic
+// ContentFieldsVideo
 type ContentFields interface {
 	implementsGraphQLInterfaceContentFields()
 	// GetName returns the interface-field "name" from its implementation.
@@ -41,8 +41,8 @@ type ContentFields interface {
 }
 
 func (v *ContentFieldsArticle) implementsGraphQLInterfaceContentFields() {}
-func (v *ContentFieldsVideo) implementsGraphQLInterfaceContentFields()   {}
 func (v *ContentFieldsTopic) implementsGraphQLInterfaceContentFields()   {}
+func (v *ContentFieldsVideo) implementsGraphQLInterfaceContentFields()   {}
 
 func __unmarshalContentFields(b []byte, v *ContentFields) error {
 	if string(b) == "null" {
@@ -61,12 +61,12 @@ func __unmarshalContentFields(b []byte, v *ContentFields) error {
 	case "Article":
 		*v = new(ContentFieldsArticle)
 		return json.Unmarshal(b, *v)
-	case "Video":
-		*v = new(ContentFieldsVideo)
-		return json.Unmarshal(b, *v)
 	case "Topic":
 		*v = new(ContentFieldsTopic)
 		return json.Unmarshal(b, *v)
+	case "Video":
+		*v = new(ContentFieldsVideo)
+		return json.Unmarshal(b, *v)
 	case "":
 		return fmt.Errorf(
 			"response was missing Content.__typename")
@@ -88,20 +88,20 @@ func __marshalContentFields(v *ContentFields) ([]byte, error) {
 			*ContentFieldsArticle
 		}{typename, v}
 		return json.Marshal(result)
-	case *ContentFieldsVideo:
-		typename = "Video"
+	case *ContentFieldsTopic:
+		typename = "Topic"
 
 		result := struct {
 			TypeName string `json:"__typename"`
-			*ContentFieldsVideo
+			*ContentFieldsTopic
 		}{typename, v}
 		return json.Marshal(result)
-	case *ContentFieldsTopic:
-		typename = "Topic"
+	case *ContentFieldsVideo:
+		typename = "Video"
 
 		result := struct {
 			TypeName string `json:"__typename"`
-			*ContentFieldsTopic
+			*ContentFieldsVideo
 		}{typename, v}
 		return json.Marshal(result)
 	case nil: