--- a/util.c	Wed Aug 23 12:10:55 2006 +0200
+++ b/util.c	Wed Aug 23 12:28:39 2006 +0200
@@ -56,7 +56,7 @@
 			if(dpy)
 				close(ConnectionNumber(dpy));
 			setsid();
-			execl(shell, shell, "-c", arg->cmd, NULL);
+			execl(shell, shell, "-c", arg->cmd, (char *)NULL);
 			fprintf(stderr, "dwm: execl '%s -c %s'", shell, arg->cmd);
 			perror(" failed");
 		}