diff --git a/wxPython/src/_defs.i b/wxPython/src/_defs.i
index 0d30488719..207b8eaf9c 100644
--- a/wxPython/src/_defs.i
+++ b/wxPython/src/_defs.i
@@ -48,6 +48,7 @@ typedef int             wxEventType;
 typedef unsigned int    size_t;
 typedef unsigned int    time_t;
 typedef unsigned char   byte;
+typedef unsigned long   wxUIntPtr;
 
 #define wxWindowID      int
 #define wxCoord         int