diff --git a/src/sys/include/ubixos/types.h b/src/sys/include/ubixos/types.h
index e004116..ce83f48 100755
--- a/src/sys/include/ubixos/types.h
+++ b/src/sys/include/ubixos/types.h
@@ -34,7 +34,9 @@
 typedef unsigned int uInt;
 
 #ifndef _STDLIB_H_
+#ifndef FALSE
 typedef enum { FALSE=0,TRUE=1 } bool;
 #endif
+#endif
 
-#endif
\ No newline at end of file
+#endif