diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 3d60771..af2ac48 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,8 +1,11 @@
 name: ci-build
 
 on:
-  - push
-  - pull_request
+  pull_request:
+    branches:
+    - '*'
+  push:
+    branches: [ main, MMU_* ]
 
 jobs:
   build: