diff --git a/README.md b/README.md
index 6177039..7d74c73 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,11 @@ as follows:
 }
 ```
 
+`yarnhook` first checks for a `yarn.lock` file. If there is one, it will only check if that file has changed, and may then run `yarn` if the `yarn.lock` has changed. If yarn.lock file is not present, it will search for files in this order, and use the corresponding "\*pm" command https://github.com/frontsideair/yarnhook/blob/29296a37a60c2771c9a45f3717c3659dbd69dbe9/index.js#L15
+
+Note that `git pull` doesn't always trigger the post-merge git hook. If it's a fast-forward update, git doesn't trigger any hooks (unless you are a for some reason actually running on a real git server, in which case, there is the `post-receive` hook)
+
+
 # Flags
 
 Prepend these flags to your git command to use them.