diff --git a/.github/workflows/phpunit.yml b/.github/workflows/phpunit.yml
index ae63da1..e202431 100644
--- a/.github/workflows/phpunit.yml
+++ b/.github/workflows/phpunit.yml
@@ -1,6 +1,10 @@
 name: PHPUnit
 
-on: [push]
+on:
+    push:
+      branches: [ "master" ]
+    pull_request:
+      branches: [ "master" ]
 
 jobs:
   build-test: