diff --git a/src/Generator/Driver.cs b/src/Generator/Driver.cs
index 8c8109aa..bd16c0d7 100644
--- a/src/Generator/Driver.cs
+++ b/src/Generator/Driver.cs
@@ -73,7 +73,7 @@ namespace CppSharp
         {
             ValidateOptions(Options);
 
-            TypeDatabase.SetupTypeMaps();
+            TypeDatabase.SetupTypeMaps(Options.GeneratorKind);
             Generator = CreateGeneratorFromKind(Options.GeneratorKind);
         }
 
diff --git a/src/Generator/Generators/CSharp/CSharpTextTemplate.cs b/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
index 7ac511dd..322f59ba 100644
--- a/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
+++ b/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
@@ -790,8 +790,8 @@ namespace CppSharp.Generators.CSharp
             // we do not support dependent fields yet, see https://github.com/mono/CppSharp/issues/197
             Class @class;
             field.Type.TryGetClass(out @class);
-            if (field.Type.IsDependent && !field.Type.IsPointer() &&
-                !(@class != null && @class.IsUnion))
+            if ((field.Type.IsDependent && !field.Type.IsPointer() &&
+                !(@class != null && @class.IsUnion)) || (@class != null && @class.TranslationUnit.IsSystemHeader))
                 return;
 
             var safeIdentifier = Helpers.SafeIdentifier(field.OriginalName);
diff --git a/src/Generator/Types/Std/Stdlib.cs b/src/Generator/Types/Std/Stdlib.cs
index 594b4fe8..515b2f03 100644
--- a/src/Generator/Types/Std/Stdlib.cs
+++ b/src/Generator/Types/Std/Stdlib.cs
@@ -26,7 +26,7 @@ namespace CppSharp.Types.Std
         }
     }
 
-    [TypeMap("std::string")]
+    [TypeMap("std::string", GeneratorKind.CLI)]
     public class String : TypeMap
     {
         public override string CLISignature(CLITypePrinterContext ctx)
@@ -305,7 +305,7 @@ namespace CppSharp.Types.Std
         }
     }
 
-    [TypeMap("std::ostream")]
+    [TypeMap("std::ostream", GeneratorKind.CLI)]
     public class OStream : TypeMap
     {
         public override string CLISignature(CLITypePrinterContext ctx)
diff --git a/src/Generator/Types/TypeMap.cs b/src/Generator/Types/TypeMap.cs
index cedd4b23..a03ccac0 100644
--- a/src/Generator/Types/TypeMap.cs
+++ b/src/Generator/Types/TypeMap.cs
@@ -15,11 +15,18 @@ namespace CppSharp.Types
     public class TypeMapAttribute : Attribute
     {
         public string Type { get; private set; }
+        public GeneratorKind? GeneratorKind { get; set; }
         
         public TypeMapAttribute(string type)
         {
             Type = type;
         }
+
+        public TypeMapAttribute(string type, GeneratorKind generatorKind)
+        {
+            Type = type;
+            GeneratorKind = generatorKind;
+        }
     }
 
     /// <summary>
@@ -117,27 +124,28 @@ namespace CppSharp.Types
             TypeMaps = new Dictionary<string, System.Type>();
         }
 
-        public void SetupTypeMaps()
+        public void SetupTypeMaps(GeneratorKind generatorKind)
         {
             var loadedAssemblies = AppDomain.CurrentDomain.GetAssemblies();
 
             foreach (var assembly in loadedAssemblies)
             {
                 var types = assembly.FindDerivedTypes(typeof(TypeMap));
-                SetupTypeMaps(types);
+                SetupTypeMaps(types, generatorKind);
             }
         }
 
-        private void SetupTypeMaps(IEnumerable<System.Type> types)
+        private void SetupTypeMaps(IEnumerable<System.Type> types, GeneratorKind generatorKind)
         {
             foreach (var typeMap in types)
             {
                 var attrs = typeMap.GetCustomAttributes(typeof(TypeMapAttribute), true);
-                if (attrs == null) continue;
-
                 foreach (TypeMapAttribute attr in attrs)
                 {
-                    TypeMaps[attr.Type] = typeMap;
+                    if (attr.GeneratorKind == null || attr.GeneratorKind == generatorKind)
+                    {
+                        TypeMaps[attr.Type] = typeMap;                        
+                    }
                 }
             }
         }
diff --git a/tests/Basic/Basic.cpp b/tests/Basic/Basic.cpp
index 5ed172db..3491e0af 100644
--- a/tests/Basic/Basic.cpp
+++ b/tests/Basic/Basic.cpp
@@ -308,3 +308,8 @@ void va_listFunction(va_list v)
 void TestDelegates::MarshalUnattributedDelegate(DelegateInGlobalNamespace del)
 {
 }
+
+std::string HasStdString::testStdString(std::string s)
+{
+    return s + "_test";
+}
diff --git a/tests/Basic/Basic.h b/tests/Basic/Basic.h
index 7627f08e..63bd1414 100644
--- a/tests/Basic/Basic.h
+++ b/tests/Basic/Basic.h
@@ -1,6 +1,7 @@
 #include "../Tests.h"
 
 #include <vadefs.h>
+#include <string>
 
 class DLL_API IgnoredType
 {
@@ -571,3 +572,11 @@ struct DLL_API TestEmptyName
         };
     };
 };
+
+class DLL_API HasStdString
+{
+    // test if these are ignored with the C# back-end
+public:
+    std::string testStdString(std::string s);
+    std::string s;
+};
diff --git a/tests/CLITemp/CLITemp.Tests.cs b/tests/CLITemp/CLITemp.Tests.cs
index 9870f259..5a58778a 100644
--- a/tests/CLITemp/CLITemp.Tests.cs
+++ b/tests/CLITemp/CLITemp.Tests.cs
@@ -1,7 +1,6 @@
 using CppSharp.Utils;
 using NUnit.Framework;
 using CLITemp;
-using System;
 
 public class CLITests : GeneratorTestFixture
 {
@@ -20,4 +19,10 @@ public class CLITests : GeneratorTestFixture
         var s = date.ToString();
         Assert.AreEqual("24/12/1924", s);
     }
+
+    [Test]
+    public void TestStdString()
+    {
+        Assert.AreEqual("test_test", CLITemp.CLITemp.testStdString("test"));
+    }
 }
\ No newline at end of file
diff --git a/tests/CLITemp/CLITemp.cpp b/tests/CLITemp/CLITemp.cpp
index 9ff8c037..7ab0c26d 100644
--- a/tests/CLITemp/CLITemp.cpp
+++ b/tests/CLITemp/CLITemp.cpp
@@ -4,3 +4,8 @@ int Types::AttributedSum(int A, int B)
 {
     return A + B;
 }
+
+std::string testStdString(std::string s)
+{
+    return s + "_test";
+}
diff --git a/tests/CLITemp/CLITemp.h b/tests/CLITemp/CLITemp.h
index 8d612e51..038bbd01 100644
--- a/tests/CLITemp/CLITemp.h
+++ b/tests/CLITemp/CLITemp.h
@@ -45,3 +45,5 @@ std::ostream& operator<<(std::ostream& os, const Date& dt)
     os << dt.mo << '/' << dt.da << '/' << dt.yr;
     return os;
 }
+
+DLL_API std::string testStdString(std::string s);