diff --git a/README.md b/README.md
index 9b6176d..3ed5851 100644
--- a/README.md
+++ b/README.md
@@ -251,7 +251,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ```yaml
 - uses: actions/checkout@v4
   with:
-    ref: ${{ github.event.pull_request.head.sha }}
+    ref: ${{ github.event.pull_request.head.sha || github.ref }}
 ```
 
 ## Checkout pull request on closed event