diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 59921d8..c61b5ef 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -1,6 +1,11 @@
 name: tzdata contents
 
-on: [push, pull_request, workflow_dispatch]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  workflow_dispatch:
 
 jobs:
   tests: