diff --git a/include/boost/intrusive/detail/mpl.hpp b/include/boost/intrusive/detail/mpl.hpp
index 1c44ca5..02b1361 100644
--- a/include/boost/intrusive/detail/mpl.hpp
+++ b/include/boost/intrusive/detail/mpl.hpp
@@ -156,10 +156,14 @@ template <typename R>
 struct is_unary_or_binary_function_impl<R (__stdcall*)()>
 {  static const bool value = true;  };
 
+#ifndef _MANAGED
+
 template <typename R>
 struct is_unary_or_binary_function_impl<R (__fastcall*)()>
 {  static const bool value = true;  };
 
+#endif
+
 template <typename R>
 struct is_unary_or_binary_function_impl<R (__cdecl*)()>
 {  static const bool value = true;  };
@@ -188,10 +192,14 @@ template <typename R, class T0>
 struct is_unary_or_binary_function_impl<R (__stdcall*)(T0)>
 {  static const bool value = true;  };
 
+#ifndef _MANAGED
+
 template <typename R, class T0>
 struct is_unary_or_binary_function_impl<R (__fastcall*)(T0)>
 {  static const bool value = true;  };
 
+#endif
+
 template <typename R, class T0>
 struct is_unary_or_binary_function_impl<R (__cdecl*)(T0)>
 {  static const bool value = true;  };
@@ -220,10 +228,14 @@ template <typename R, class T0, class T1>
 struct is_unary_or_binary_function_impl<R (__stdcall*)(T0, T1)>
 {  static const bool value = true;  };
 
+#ifndef _MANAGED
+
 template <typename R, class T0, class T1>
 struct is_unary_or_binary_function_impl<R (__fastcall*)(T0, T1)>
 {  static const bool value = true;  };
 
+#endif
+
 template <typename R, class T0, class T1>
 struct is_unary_or_binary_function_impl<R (__cdecl*)(T0, T1)>
 {  static const bool value = true;  };