diff --git a/.github/ng-renovate/runner-config.js b/.github/ng-renovate/runner-config.js
index a612ad80b..a2fda9cfd 100644
--- a/.github/ng-renovate/runner-config.js
+++ b/.github/ng-renovate/runner-config.js
@@ -4,6 +4,9 @@ module.exports = {
   platform: 'github',
   branchNameStrict: true,
   forkMode: true,
+  // Renovate fork PRs should never be editable as Renovate would otherwise
+  // not be able to delete the branches and future updates would be missed.
+  forkModeDisallowMaintainerEdits: true,
   onboarding: false,
   persistRepoData: true,
   allowedPostUpgradeCommands: ['.'],