diff --git a/programs/_updown.netkey/_updown.netkey.in b/programs/_updown.netkey/_updown.netkey.in
index 9c76998233..21000b1ea4 100644
--- a/programs/_updown.netkey/_updown.netkey.in
+++ b/programs/_updown.netkey/_updown.netkey.in
@@ -446,7 +446,7 @@ delsource() {
         return ${st}
     fi
     # Remove source ip if it's not used any more.
-    if [ -z $(ip -o route list src ${PLUTO_MY_SOURCEIP}) ]; then
+    if [ -z "$(ip -o route list src ${PLUTO_MY_SOURCEIP})" ]; then
 	if [ -n "${VTI_IFACE}" -a "${VTI_ROUTING}" = yes ]; then
 	    interface="${VTI_IFACE}"
 	fi