diff --git a/Source/ResourceEditor.h b/Source/ResourceEditor.h
index a730c900..0aaaadc0 100644
--- a/Source/ResourceEditor.h
+++ b/Source/ResourceEditor.h
@@ -41,6 +41,9 @@
 using namespace std;
 
 #ifndef IS_INTRESOURCE
+#ifndef ULONG_PTR
+#define ULONG_PTR DWORD
+#endif
 #define IS_INTRESOURCE(_r) (((ULONG_PTR)(_r) >> 16) == 0)
 #endif