diff --git a/Engine/lib/opcode/OPC_HybridModel.cpp b/Engine/lib/opcode/OPC_HybridModel.cpp
index a8e0e9c6e..3aa162121 100644
--- a/Engine/lib/opcode/OPC_HybridModel.cpp
+++ b/Engine/lib/opcode/OPC_HybridModel.cpp
@@ -82,7 +82,16 @@
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 #include "Opcode.h"
+
+#if (defined _MSC_VER) && (_MSC_VER <= 1500)
+#ifdef _WIN64 // [
+typedef unsigned __int64  uintptr_t;
+#else // _WIN64 ][
+typedef _W64 unsigned int uintptr_t;
+#endif // _WIN64 ]
+#else
 #include <stdint.h>
+#endif
 
 using namespace Opcode;
 
diff --git a/Engine/lib/opcode/OPC_SweepAndPrune.cpp b/Engine/lib/opcode/OPC_SweepAndPrune.cpp
index b7ee4183e..960c8863d 100644
--- a/Engine/lib/opcode/OPC_SweepAndPrune.cpp
+++ b/Engine/lib/opcode/OPC_SweepAndPrune.cpp
@@ -17,7 +17,16 @@
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 #include "Opcode.h"
+
+#if (defined _MSC_VER) && (_MSC_VER <= 1500)
+#ifdef _WIN64 // [
+typedef unsigned __int64  uintptr_t;
+#else // _WIN64 ][
+typedef _W64 unsigned int uintptr_t;
+#endif // _WIN64 ]
+#else
 #include <stdint.h>
+#endif
 
 using namespace Opcode;