diff --git a/distrib/sets/getdirs.awk b/distrib/sets/getdirs.awk
index f82e6a2a6a90..869b203f4a4b 100644
--- a/distrib/sets/getdirs.awk
+++ b/distrib/sets/getdirs.awk
@@ -1,4 +1,4 @@
-#	$NetBSD: getdirs.awk,v 1.5 2012/02/08 16:51:09 njoly Exp $
+#	$NetBSD: getdirs.awk,v 1.6 2013/03/12 13:08:00 njoly Exp $
 #
 # Copyright (c) 2002 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -59,6 +59,15 @@ function dirname(file) \
 	exit 1
 }
 
+#	error if path has a trailing slash
+#
+/\/$/ \
+{
+	print "Unsupported path with trailing slash:" >"/dev/stderr"
+	print >"/dev/stderr"
+	exit 1
+}
+
 #	all other lines are parsed 
 #
 {