diff --git a/.hg_helpers/hooks/ctags-hook b/.hg_helpers/hooks/ctags-hook
new file mode 100755
--- /dev/null
+++ b/.hg_helpers/hooks/ctags-hook
@@ -0,0 +1,6 @@
+#!/bin/sh
+# in repo .hg/hgrc:
+# [hooks]
+# changegroup = ~/.hg_helpers/hooks/ctags-hook
+export CTAGS_HOOK=1
+~/.hg_helpers/ctags </dev/null >/dev/null 2>&1 &