diff --git a/README.md b/README.md
index 8d5a116..0798ff7 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,11 @@ This action runs `docker build --check` with reviewdog on pull requests to impro
 ```yaml
 name: reviewdog
 
-on: [pull_request]
+on: 
+  pull_request:
+    paths:
+      - '**/Dockerfile'
+
 
 permissions:
   contents: read