diff --git a/usr.bin/unifdef/unifdefall.sh b/usr.bin/unifdef/unifdefall.sh
index 5625eb970211..bcba08c9712b 100644
--- a/usr.bin/unifdef/unifdefall.sh
+++ b/usr.bin/unifdef/unifdefall.sh
@@ -2,7 +2,7 @@
 #
 # remove all the #if's from a source file
 #
-#	$dotat: things/unifdefall.sh,v 1.8 2002/05/15 10:31:20 fanf Exp $
+#	$dotat: things/unifdefall.sh,v 1.9 2002/09/24 19:43:57 fanf2 Exp $
 # $FreeBSD$
 
 set -e
@@ -17,7 +17,7 @@ sed -Ee 's/^([A-Za-z0-9_]+).*$/\1/' $tmp/hashdefs > $tmp/alldef
 comm -23 $tmp/ctrl $tmp/alldef > $tmp/undef
 comm -12 $tmp/ctrl $tmp/alldef > $tmp/def
 
-echo unifdef \\ > $tmp/cmd
+echo unifdef -k \\ > $tmp/cmd
 sed -Ee 's/^(.*)$/-U\1 \\/' $tmp/undef >> $tmp/cmd
 while read sym
 do	sed -Ee '/^('"$sym"')([(][^)]*[)])?([ 	]+(.*))?$/!d;s//-D\1=\4/' $tmp/hashdefs