diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index 998ba67..0904c2e 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -1,6 +1,9 @@
 name: Python package
 
-on: [push, pull_request]
+on:
+  push:
+    branches: master
+  pull_request:
 
 jobs:
   ruff: