diff --git a/README.md b/README.md
index 8b5af319..d668358d 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,8 @@ feed:
 
 To note, you shouldn't have to do this unless you already have a feed you're using, and you can't or wish not to redirect existing subscribers.
 
+<span role="img" aria-label="Warning">⚠️</span> If your feed path does not end with `.xml`, you'll need to configure your web server to serve the proper Content-Type. Alternatively, you can specify e.g. `feed/index.xml` to serve your feed from `/feed/`.
+
 ### Optional front matter
 
 The plugin will use the following post metadata, automatically generated by Jekyll, which you can override via a post's YAML front matter: