diff --git a/contrib/ipfilter/tools/ipmon.c b/contrib/ipfilter/tools/ipmon.c
index d08895a85c34..d7ad1a228378 100644
--- a/contrib/ipfilter/tools/ipmon.c
+++ b/contrib/ipfilter/tools/ipmon.c
@@ -1442,7 +1442,7 @@ static void usage(prog)
 		"\t[ -f <device> ] [ -L <facility> ] [ -N <device> ]\n"
 		"\t[ -o [NSI] ] [ -O [NSI] ] [ -P <pidfile> ] [ -S <device> ]\n"
 		"\t[ <filename> ]\n", prog);
-	exit(-1);
+	exit(1);
 }