diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1762fbd4..19b172cc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,9 +2,9 @@ name: build
 
 on:
   push:
-    branches: [ unstable ]
+    branches: [ unstable, '[0-9]+.[0-9]+.x' ]
   pull_request:
-    branches: [ unstable ]
+    branches: [ unstable, '[0-9]+.[0-9]+.x' ]
   workflow_call:
   workflow_dispatch: