diff --git a/src/mesa/main/glheader.h b/src/mesa/main/glheader.h
index 533e4a2bd8d..6f3b2089c33 100644
--- a/src/mesa/main/glheader.h
+++ b/src/mesa/main/glheader.h
@@ -72,6 +72,12 @@
 #  if _MSC_VER == 1200
      typedef UINT_PTR uintptr_t;
 #  endif 
+#elif defined(__INTERIX)
+/* Interix 3.x has a gcc that shadows this. */
+#  ifndef _UINTPTR_T_DEFINED
+     typedef unsigned long uintptr_t;
+#  define _UINTPTR_T_DEFINED
+#  endif
 #else
 #  include <inttypes.h>
 #endif