diff --git a/src/Generator/Passes/CheckAmbiguousFunctions.cs b/src/Generator/Passes/CheckAmbiguousFunctions.cs
index 4a8517ab..a164ac1f 100644
--- a/src/Generator/Passes/CheckAmbiguousFunctions.cs
+++ b/src/Generator/Passes/CheckAmbiguousFunctions.cs
@@ -2,6 +2,7 @@
 using System.Linq;
 using CppSharp.AST;
 using CppSharp.AST.Extensions;
+using CppSharp.Types;
 
 namespace CppSharp.Passes
 {
@@ -65,17 +66,17 @@ namespace CppSharp.Passes
             return true;
         }
 
-        private static bool CheckDefaultParametersForAmbiguity(Function function, Function overload)
+        private bool CheckDefaultParametersForAmbiguity(Function function, Function overload)
         {
             var commonParameters = Math.Min(function.Parameters.Count, overload.Parameters.Count);
 
             var i = 0;
             for (; i < commonParameters; ++i)
             {
-                var funcParam = function.Parameters[i];
-                var overloadParam = overload.Parameters[i];
+                AST.Type funcType = GetFinalType(function.Parameters[i]);
+                AST.Type overloadType = GetFinalType(overload.Parameters[i]);
 
-                if (!funcParam.QualifiedType.Equals(overloadParam.QualifiedType))
+                if (!funcType.Equals(overloadType))
                     return false;
             }
 
@@ -101,6 +102,30 @@ namespace CppSharp.Passes
             return true;
         }
 
+        private AST.Type GetFinalType(Parameter parameter)
+        {
+            TypeMap typeMap;
+            if (Context.TypeMaps.FindTypeMap(parameter.Type, out typeMap))
+            {
+                var typePrinterContext = new TypePrinterContext
+                {
+                    Kind = TypePrinterContextKind.Managed,
+                    Parameter = parameter,
+                    Type = typeMap.Type
+                };
+
+                switch (Options.GeneratorKind)
+                {
+                    case Generators.GeneratorKind.CLI:
+                        return typeMap.CLISignatureType(typePrinterContext).Desugar();
+                    case Generators.GeneratorKind.CSharp:
+                        return typeMap.CSharpSignatureType(typePrinterContext).Desugar();
+                }
+            }
+
+            return parameter.Type.Desugar();
+        }
+
         private static bool CheckConstnessForAmbiguity(Function function, Function overload)
         {
             var method1 = function as Method;
diff --git a/tests/CSharp/CSharp.Tests.cs b/tests/CSharp/CSharp.Tests.cs
index 0173bcf1..14744a22 100644
--- a/tests/CSharp/CSharp.Tests.cs
+++ b/tests/CSharp/CSharp.Tests.cs
@@ -35,6 +35,7 @@ public unsafe class CSharpTests : GeneratorTestFixture
         new InheritanceBuffer().Dispose();
         new HasProtectedVirtual().Dispose();
         new Proprietor(5).Dispose();
+        new HasCtorWithMappedToEnum<TestFlag>(TestFlag.Flag1).Dispose();
         using (var testOverrideFromSecondaryBase = new TestOverrideFromSecondaryBase())
         {
             testOverrideFromSecondaryBase.function();
diff --git a/tests/CSharp/CSharp.cpp b/tests/CSharp/CSharp.cpp
index 81b050d0..586e7ece 100644
--- a/tests/CSharp/CSharp.cpp
+++ b/tests/CSharp/CSharp.cpp
@@ -1,4 +1,6 @@
-#include "CSharp.h"
+#pragma once
+
+#include "CSharp.h"
 
 Foo::Foo(const char* name)
 {
@@ -322,9 +324,12 @@ ComplexType::ComplexType() : qFlags(QFlags<TestFlag>(TestFlag::Flag2))
 {
 }
 
-ComplexType::ComplexType(const QFlags<TestFlag> f) : qFlags(QFlags<TestFlag>(TestFlag::Flag2))
+ComplexType::ComplexType(const QFlags<TestFlag> f) : qFlags(f)
+{
+}
+
+ComplexType::ComplexType(const HasCtorWithMappedToEnum<TestFlag> f)
 {
-    qFlags = f;
 }
 
 int ComplexType::check()
diff --git a/tests/CSharp/CSharp.h b/tests/CSharp/CSharp.h
index b7428ecf..aa8755ad 100644
--- a/tests/CSharp/CSharp.h
+++ b/tests/CSharp/CSharp.h
@@ -1,9 +1,12 @@
+#pragma once
+
 #include "../Tests.h"
 #include <cstdint>
 #include <vector>
 #include <limits>
 #include <string>
 #include "AnotherUnit.h"
+#include "CSharpTemplates.h"
 
 class DLL_API Foo
 {
@@ -184,46 +187,12 @@ private:
 
 Proprietor::Proprietor() : _items(Bar::Items::Item1), _itemsByValue(Bar::Items::Item1) {}
 
-template <typename T>
-class DLL_API QFlags
-{
-    typedef int Int;
-    typedef int (*Zero);
-public:
-    QFlags(T t);
-    QFlags(Zero = 0);
-    operator Int();
-private:
-    int flag;
-};
-
-template <typename T>
-QFlags<T>::QFlags(T t) : flag(Int(t))
-{
-}
-
-template <typename T>
-QFlags<T>::QFlags(Zero) : flag(Int(0))
-{
-}
-
-template <typename T>
-QFlags<T>::operator Int()
-{
-    return flag;
-}
-
-enum class TestFlag
-{
-    Flag1,
-    Flag2
-};
-
 class DLL_API ComplexType
 {
 public:
     ComplexType();
     ComplexType(const QFlags<TestFlag> f);
+    ComplexType(const HasCtorWithMappedToEnum<TestFlag> f);
     int check();
     QFlags<TestFlag> returnsQFlags();
     void takesQFlags(const QFlags<int> f);
diff --git a/tests/CSharp/CSharpTemplates.h b/tests/CSharp/CSharpTemplates.h
index 2f4d2117..e773241c 100644
--- a/tests/CSharp/CSharpTemplates.h
+++ b/tests/CSharp/CSharpTemplates.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "../Tests.h"
 #include "AnotherUnit.h"
 
@@ -606,6 +608,59 @@ enum class UsedInTemplatedIndexer
     Item2
 };
 
+template <typename T>
+class DLL_API QFlags
+{
+    typedef int Int;
+    typedef int (*Zero);
+public:
+    QFlags(T t);
+    QFlags(Zero = 0);
+    operator Int();
+private:
+    int flag;
+};
+
+template <typename T>
+QFlags<T>::QFlags(T t) : flag(Int(t))
+{
+}
+
+template <typename T>
+QFlags<T>::QFlags(Zero) : flag(Int(0))
+{
+}
+
+template <typename T>
+QFlags<T>::operator Int()
+{
+    return flag;
+}
+
+template <typename T>
+class HasCtorWithMappedToEnum
+{
+public:
+    HasCtorWithMappedToEnum(QFlags<T> t);
+    HasCtorWithMappedToEnum(T t);
+};
+
+template <typename T>
+HasCtorWithMappedToEnum<T>::HasCtorWithMappedToEnum(QFlags<T> t)
+{
+}
+
+template <typename T>
+HasCtorWithMappedToEnum<T>::HasCtorWithMappedToEnum(T t)
+{
+}
+
+enum class TestFlag
+{
+    Flag1,
+    Flag2
+};
+
 // we optimise specialisations so that only actually used ones are wrapped
 void forceUseSpecializations(IndependentFields<int> _1, IndependentFields<bool> _2,
                              IndependentFields<T1> _3, IndependentFields<std::string> _4,
@@ -643,6 +698,7 @@ template class DLL_API TemplateWithIndexer<T1>;
 template class DLL_API TemplateWithIndexer<T2*>;
 template class DLL_API TemplateWithIndexer<float>;
 template class DLL_API TemplateDerivedFromRegularDynamic<RegularDynamic>;
+template class DLL_API HasCtorWithMappedToEnum<TestFlag>;
 
 class TestForwardedClassInAnotherUnit;