diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7f5225c5..a6649201 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,6 +1,12 @@
 name: Python Fire
 
-on: [push]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
 
 jobs:
   build: