diff --git a/src/xpdev/gen_defs.h b/src/xpdev/gen_defs.h
index 1424f4c88aa59ab01766e3f0159b74a989eeff93..af69f34aa6b637bc0ccbc58a2128e244d030ade7 100644
--- a/src/xpdev/gen_defs.h
+++ b/src/xpdev/gen_defs.h
@@ -171,7 +171,9 @@ typedef unsigned long long int uint64_t;
 #endif
 
 typedef uint64_t	uintmax_t;
+#define _UINTMAX_T_DECLARED
 typedef int64_t		intmax_t;
+#define _INTMAX_T_DECLARED
 
 /* printf integer formatters: */