diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 02b2706..72b449c 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,19 +1,20 @@
+# Version updates run on demand, to keep the number of open pull requests
+# manageable: trigger them from Insights > Dependency graph > Dependabot >
+# "Check for updates". Dependabot has no manual-only schedule, so the
+# semiannual interval below (every six months) is only a fallback.
 version: 2
 updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
-      day: "monday"
+      interval: "semiannually"
 
   - package-ecosystem: "docker"
     directory: "/tutorcredentials/templates/credentials/build/credentials"
     schedule:
-      interval: "weekly"
-      day: "monday"
+      interval: "semiannually"
 
   - package-ecosystem: "pip"
     directory: "/"
     schedule:
-      interval: "weekly"
-      day: "monday"
+      interval: "semiannually"