diff --git a/.github/workflows/action.yml b/.github/workflows/action.yml
index 04a60dc..3c71f3d 100644
--- a/.github/workflows/action.yml
+++ b/.github/workflows/action.yml
@@ -1,6 +1,12 @@
 name: Check Markdown links
 
-on: push
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
 
 jobs:
   markdown-link-check: