diff --git a/README.md b/README.md
index 58179fa..462d90b 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@
 
 > "Think globally, <code>act</code> locally"
 
+__Currently this library only supports the HCL syntax, not the YAML syntax__
+
 Run your [GitHub Actions](https://developer.github.com/actions/) locally! Why would you want to do this? Two reasons:
 
 * **Fast Feedback** - Rather than having to commit/push every time you want test out the changes you are making to your `.github/workflows/` files (or for any changes to embedded GitHub actions), you can use `act` to run the actions locally. The [environment variables](https://help.github.com/en/actions/configuring-and-managing-workflows/using-environment-variables#default-environment-variables) and [filesystem](https://help.github.com/en/actions/reference/virtual-environments-for-github-hosted-runners#filesystems-on-github-hosted-runners) are all configured to match what GitHub provides.