diff --git a/.github/workflows/update-flake-lock.yaml b/.github/workflows/update-flake-lock.yaml
index c4e7fd0..3d3a502 100644
--- a/.github/workflows/update-flake-lock.yaml
+++ b/.github/workflows/update-flake-lock.yaml
@@ -3,7 +3,7 @@ name: update-flake-lock
 on:
   workflow_dispatch: # enable manual triggering
   schedule:
-    - cron: '0 0 * * 0' # every Sunday at midnight
+    - cron: '0 0 */15 * *' # every 15th day of the month
 
 jobs:
   lockfile: