diff --git a/ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs b/ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs
index 63aafbd216..13aecd79d8 100644
--- a/ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs
+++ b/ICSharpCode.NRefactory.CSharp/Resolver/OverloadResolution.cs
@@ -950,7 +950,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			if (member == null)
 				throw new InvalidOperationException();
 			
-			if (this.IsExtensionMethodInvocation)
+			if (this.IsExtensionMethodInvocation && member is SpecializedMethod)
 				((SpecializedMethod)member).IsExtendedExtensionMethod = true;
 			return new CSharpInvocationResolveResult(
 				this.IsExtensionMethodInvocation ? new TypeResolveResult(member.DeclaringType) : targetResolveResult,