diff --git a/.github/workflows/config.yml b/.github/workflows/config.yml
index 347edb097..043b9d664 100644
--- a/.github/workflows/config.yml
+++ b/.github/workflows/config.yml
@@ -1,6 +1,11 @@
 name: CI
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  # Run weakly at 00:00 on Sunday.
+  schedule:
+  - cron:  '0 0 * * 0'
 
 jobs:
   build: