diff --git a/README.md b/README.md
index a9a155f9..a7681ae1 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,7 @@ The `env` portion of the workflow must be configured before the action will work
 | ------------- | ------------- | ------------- |
 | `BUILD_SCRIPT`  | If you require a build script to compile your code prior to pushing it you can add the script here. The Docker container which powers the action runs Node which means `npm` commands are valid. If you're using a static site generator I'd suggest building the code prior to pushing it.  | **No** |
 | `BRANCH`  | This is the branch you wish to deploy to, for example `gh-pages` or `docs`.  | **Yes** |
+| `BASE_BRANCH`  | The base branch of your repository which you'd like to checkout prior to deploying. This defaults to `master`.  | **No** |
 | `FOLDER`  | The folder in your repository that you want to deploy. If your build script compiles into a directory named `build` you'd put it in here.  | **Yes** |
 | `COMMIT_NAME`  | Used to sign the commit, this should be your name.   | **No** |
 | `COMMIT_EMAIL`  | Used to sign the commit, this should be your email. | **No** |