diff --git a/headers/posix/stdint.h b/headers/posix/stdint.h
index 03e66957bc..b90fca2109 100644
--- a/headers/posix/stdint.h
+++ b/headers/posix/stdint.h
@@ -70,10 +70,10 @@ typedef uint64_t uintmax_t;
 #define UINT32_MAX	(4294967295U)
 
 #if defined(__SIZEOF_LONG__) && __SIZEOF_LONG__ > 4
-#define INT64_MAX	(9223372036854775807UL)
+#define INT64_MAX	(9223372036854775807L)
 #define UINT64_MAX	(18446744073709551615UL)
 #else
-#define INT64_MAX	(9223372036854775807ULL)
+#define INT64_MAX	(9223372036854775807LL)
 #define UINT64_MAX	(18446744073709551615ULL)
 #endif
 #define INT64_MIN	(-INT64_MAX-1)