diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4af6e9e..cb4a78f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,5 +1,8 @@
 name: CI
-on: push
+on:
+  pull_request:
+    branches:
+      - master
 jobs:
   test:
     runs-on: ubuntu-latest