diff --git a/.github/workflows/repo-maintenance.yaml b/.github/workflows/repo-maintenance.yaml
index 0fb1027a8..0421efe6e 100644
--- a/.github/workflows/repo-maintenance.yaml
+++ b/.github/workflows/repo-maintenance.yaml
@@ -89,6 +89,14 @@ jobs:
             const { owner, repo } = context.repo;
             const upstream = `${owner}/${repo}`;
 
+            const closed = context.payload.pull_request;
+            if (closed) {
+              if (closed.head.repo?.full_name === upstream) {
+                await github.rest.git.deleteRef({ owner, repo, ref: `heads/${closed.head.ref}` }).catch(console.log);
+              }
+              return;
+            }
+
             for await (const response of github.paginate.iterator(github.rest.pulls.list, {
               owner,
               repo,