diff --git a/src/Runtime/Helpers.cs b/src/Runtime/Helpers.cs
index 0a3d8ba2..0962c1a4 100644
--- a/src/Runtime/Helpers.cs
+++ b/src/Runtime/Helpers.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Concurrent;
 using System.Runtime.InteropServices;
 using System.Text;
 
@@ -21,12 +20,5 @@ namespace CppSharp.Runtime
 
             return encoding.GetString(buffer);
         }
-
-#if WINDOWS
-        [DllImport("msvcrt.dll", EntryPoint = "memcpy", CallingConvention = CallingConvention.Cdecl)]
-#else
-        [DllImport("libc", EntryPoint = "memcpy")]
-#endif
-        public static extern IntPtr memcpy(IntPtr dest, IntPtr src, UIntPtr count);
     }
 }
diff --git a/src/Runtime/Interfaces.cs b/src/Runtime/Interfaces.cs
deleted file mode 100644
index 40eb3465..00000000
--- a/src/Runtime/Interfaces.cs
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Copyright (c) 2013 Xamarin, Inc and contributors
- * 
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to
-  * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- * 
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
-
-using System;
-
-namespace CppSharp.Runtime
-{
-    public interface ICppMarshal
-    {
-        /// <summary>
-        /// Gets the native data size for the object.
-        /// </summary>
-        int NativeDataSize { get; }
-
-        /// <summary>
-        /// Converts the managed data to unmanaged data.
-        /// </summary>/// 
-        void MarshalManagedToNative(IntPtr instance);
-
-        /// <summary>
-        /// Converts the unmanaged data to managed data.
-        /// </summary>
-        void MarshalNativeToManaged(IntPtr instance);
-    }
-}