diff --git a/z.sh b/z.sh
index 65e41b8..132904e 100644
--- a/z.sh
+++ b/z.sh
@@ -79,7 +79,7 @@ _z() {
         if [ $? -ne 0 -a -f "$datafile" ]; then
             env rm -f "$tempfile"
         else
-	    [ -n "$_Z_OWNER" ] && chown $_Z_OWNER:$(id -ng $_Z_OWNER) "$tempfile"
+            [ "$_Z_OWNER" ] && chown $_Z_OWNER:$(id -ng $_Z_OWNER) "$tempfile"
             env mv -f "$tempfile" "$datafile" || env rm -f "$tempfile"
         fi