diff --git a/.forgejo/workflows/cascade-forgejo.yml b/.forgejo/workflows/cascade-forgejo.yml
index 1f371dfd..15063e7a 100644
--- a/.forgejo/workflows/cascade-forgejo.yml
+++ b/.forgejo/workflows/cascade-forgejo.yml
@@ -30,6 +30,7 @@ on:
     types:
       - synchronize
       - labeled
+      - closed
 
 enable-email-notifications: true
 
@@ -63,6 +64,7 @@ jobs:
     # If this is a pull request, run
     #   - when the `run-forgejo-tests` label is set (label_updated) (but not if another label is set or if a label is removed)
     #   - when a new commit is pushed to the pull request (synchronized) if the `run-forgejo-tests` is already present
+    #   - when the pull request is closed, which also happens when it is merged, so that the Forgejo pull request is closed
     #
     if: >
       vars.ROLE == 'forgejo-coding' && (
@@ -70,6 +72,7 @@ jobs:
           forge.event_name == 'push' && ( forge.ref_name == 'main' || forge.ref_name == 'wip-cascade')
         ) || (
           forge.event_name == 'pull_request_target' && (
+            forge.event.action == 'closed' ||
             ( forge.event.action == 'synchronized' && contains(forge.event.pull_request.labels.*.name, 'run-forgejo-tests') ) ||
             ( forge.event.action == 'label_updated' && forge.event.label.name == 'run-forgejo-tests' )
           )