diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 09b18d9..39098aa 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -7,7 +7,7 @@ on:
   pull_request:
     branches: [main, master]
   schedule:
-    - cron: '0 6 * * 1'
+    - cron: '0 6 1 * *'   # monthly 1st 06:00 UTC
 
 permissions:
   contents: read