diff --git a/docs/nextstrain-internal/pathogen-repo-ci.md b/docs/nextstrain-internal/pathogen-repo-ci.md
index 22867d6..608838b 100644
--- a/docs/nextstrain-internal/pathogen-repo-ci.md
+++ b/docs/nextstrain-internal/pathogen-repo-ci.md
@@ -20,6 +20,10 @@ on:
       - main
   pull_request:
   workflow_dispatch:
+  # Routinely check that we continue to work in the face of external changes.
+  schedule:
+    # Every day at 18:37 UTC / 10:37 Seattle (winter) / 11:37 Seattle (summer)
+    - cron: "37 18 * * *"
 
 jobs:
   ci: