--- a/.bash_prompt	Wed Sep 03 22:21:33 2014 +0900
+++ b/.bash_prompt	Wed Sep 03 22:54:11 2014 +0900
@@ -25,8 +25,6 @@
 
     local TIME="${G}\t${RESET}"
 
-    local USE_HG_PROMPT=
-
     if [[ $RETURN_CODE != 0 ]] ; then
         local RETCODE="${R}${RETURN_CODE}${RESET} "
     fi
@@ -121,5 +119,10 @@
 ${PROMPT_COLOR}\\\$${RESET} "
 }
 
+# first find prompt in hgrc, then check it's actually enabled
+if grep -w '^prompt' ~/.hgrc &>/dev/null && hg help prompt &>/dev/null ; then
+    USE_HG_PROMPT=1
+fi
+
 export VIRTUAL_ENV_DISABLE_PROMPT=1
 export PROMPT_COMMAND=prompt_command