diff --git a/themes/agnoster.zsh-theme b/themes/agnoster.zsh-theme
index 6aa484760..7fb7d108e 100644
--- a/themes/agnoster.zsh-theme
+++ b/themes/agnoster.zsh-theme
@@ -127,9 +127,8 @@ prompt_git() {
   fi
 }
 
-prompt_hg() {
-  which hg > /dev/null 2>&1
-  if [[ $? -ne 0 ]]; then
+prompt_hg()
+  if ! type hg &> /dev/null ; then
     return
   fi
   local rev status