diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 714253bf..c3eba474 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [ master, main ]
+    branches: [ master, main, 0.4.x ]
   pull_request:
-    branches: [ master, main ]
+    branches: [ master, main, 0.4.x ]
 
 jobs:
   test: