diff --git a/ondir_prompt_hook.fish b/ondir_prompt_hook.fish
new file mode 100644
index 0000000..28aa802
--- /dev/null
+++ b/ondir_prompt_hook.fish
@@ -0,0 +1,6 @@
+# copy this file to ~/.config/fish/functions
+function ondir_prompt_hook --on-event fish_prompt
+    if test ! -e "$OLDONDIRWD"; set -g OLDONDIRWD /; end;
+    if [ "$OLDONDIRWD" != "$PWD" ]; eval (ondir $OLDONDIRWD $PWD); end;
+    set -g OLDONDIRWD "$PWD";
+end