diff --git a/headers/posix/size_t.h b/headers/posix/size_t.h
index c8f2e7e743..4592b897c1 100644
--- a/headers/posix/size_t.h
+++ b/headers/posix/size_t.h
@@ -5,14 +5,15 @@
 #ifndef _SIZE_T_H_
 #define _SIZE_T_H_
 
+
 #include <stddef.h>
 
-/* ATM we don't define ssize_t for GCC2 */
-#if __GNUC__ > 2 
-#ifndef __ssize_t__
-#define __ssize_t__
-typedef long signed int	ssize_t;
-#endif /* __ssize_t__ */
-#endif /* __GNUC__ > 2 */
 
-#endif /* _SIZE_T_H_ */
+/* ATM we don't define ssize_t for GCC2 */
+#if __GNUC__ > 2 && !defined(__ssize_t__)
+#	define __ssize_t__
+typedef long signed int	ssize_t;
+#endif
+
+
+#endif	/* _SIZE_T_H_ */