Index: uspace/lib/c/include/unistd.h
===================================================================
--- uspace/lib/c/include/unistd.h	(revision 06e2209d02210259a59f87828be53a89bc15a4c0)
+++ uspace/lib/c/include/unistd.h	(revision 74c579084c8b9609f2f13a636f829296ce55ddfe)
@@ -41,5 +41,5 @@
 
 #ifndef NULL
-	#define NULL  0
+	#define NULL  0UL
 #endif