diff --git a/src/OneScript.Core/Commons/IndexedNameValueCollection.cs b/src/OneScript.Core/Commons/IndexedNameValueCollection.cs
index 059764382..94e2631ff 100644
--- a/src/OneScript.Core/Commons/IndexedNameValueCollection.cs
+++ b/src/OneScript.Core/Commons/IndexedNameValueCollection.cs
@@ -58,7 +58,7 @@ public T this[string name]
         public void AddName(int index, string name)
         {
             if (index < 0 || index >= _values.Count)
-                throw new ArgumentOutOfRangeException();
+                throw new ArgumentOutOfRangeException(nameof(index));
 
             _nameIndex[name] = index;
         }
diff --git a/src/OneScript.Language/IdentifiersTrie.cs b/src/OneScript.Language/IdentifiersTrie.cs
index cacf088fb..df4b68a19 100644
--- a/src/OneScript.Language/IdentifiersTrie.cs
+++ b/src/OneScript.Language/IdentifiersTrie.cs
@@ -74,17 +74,17 @@ public void Add(string str, T val)
             node.Value = val;
         }
 
-        public bool ContainsKey(string str)
+        public bool ContainsKey(string key)
         {
             var node = _root;
-            foreach (char ch in str)
+            foreach (char ch in key)
             {
-                var key = node.Find(ch);
-                if (key == null)
+                var keyNode = node.Find(ch);
+                if (keyNode == null)
                 {
                     return false;
                 }
-                node = key.next;
+                node = keyNode.next;
             }
 
             return node.next == null && node.HasValue;
diff --git a/src/OneScript.StandardLibrary/Xml/XmlGlobalFunctions.cs b/src/OneScript.StandardLibrary/Xml/XmlGlobalFunctions.cs
index 9d75a67ed..48acbc43b 100644
--- a/src/OneScript.StandardLibrary/Xml/XmlGlobalFunctions.cs
+++ b/src/OneScript.StandardLibrary/Xml/XmlGlobalFunctions.cs
@@ -138,21 +138,15 @@ public IValue XMLValue(IValue givenType, string presentation)
             {
                 if (presentation.Trim() == "")
                     return ValueFactory.Create();
-                else
-                {
-                    throw RuntimeException.InvalidNthArgumentValue(2);
-                }
-                return ValueFactory.Create();
+                
+                throw RuntimeException.InvalidNthArgumentValue(2);
             }
             else if (typeValue.Equals(BasicTypes.Null))
             {
                 if (presentation.Trim() == "")
                     return ValueFactory.CreateNullValue();
-                else
-                {
-                    throw RuntimeException.InvalidNthArgumentValue(2);
-                }
-                return ValueFactory.Create();
+                
+                throw RuntimeException.InvalidNthArgumentValue(2);
             }
             else if (typeValue.ImplementingClass == typeof(GuidWrapper))
             {