--- a/contrib/zsh_completion
+++ b/contrib/zsh_completion
@@ -519,6 +519,7 @@ typeset -A _hg_cmd_globals
 _hg_qguards() {
   typeset -a guards
   local guard
+  compset -P "+|-"
   _hg_cmd qselect -s | while read guard
   do
     guards+=(${guard#(+|-)})