diff --git a/cascading-pr.sh b/cascading-pr.sh
index 977a8ff..3b42f33 100755
--- a/cascading-pr.sh
+++ b/cascading-pr.sh
@@ -108,6 +108,10 @@ function pr_head() {
     pr $1 | jq --raw-output .head.ref
 }
 
+function pr_merged() {
+    pr $1 | jq --raw-output .merged
+}
+
 function upsert_clone() {
     local direction=$1 branch=$2 clone=$3
 
@@ -154,7 +158,7 @@ function update() {
     (
 	cd $TMPDIR/origin
 	ls -l  $TMPDIR/destination
-	${options[update]} $TMPDIR/destination
+	${options[update]} $TMPDIR/destination $TMPDIR/destination-pr.json $TMPDIR/origin-pr.json
     )
     push destination ${options[destination_head]} ${options[destination_clone]}
 }
@@ -188,9 +192,17 @@ function run() {
 	    wait_destination_ci $(cat $TMPDIR/destination.sha)
 	    ;;
 	closed)
-	    log_info "PR is closed, close the cascade PR and remove the branch"
-	    repo_login ${options[destination_repo]}
-	    close_pr destination
+	    if "$(pr_merged origin)"; then
+		log_info "PR was merged, update the cascade PR"
+		repo_login ${options[destination_repo]}
+		pr origin
+		pr destination
+		update
+	    else
+		log_info "PR is closed, close the cascade PR and remove the branch"
+		repo_login ${options[destination_repo]}
+		close_pr destination
+	    fi
 	    ;;
 	*)
 	    log_info "state '$state', do nothing"
diff --git a/tests/originrepo/upgraded b/tests/originrepo/upgraded
index ee39223..8b37734 100755
--- a/tests/originrepo/upgraded
+++ b/tests/originrepo/upgraded
@@ -1,5 +1,13 @@
 #!/bin/bash
 
-destination="$1"
+set -ex
 
-date +%s > $destination/last
+destination_checkout="$1"
+destination_pr_json="$2"
+origin_pr_json="$3"
+
+test -d $destination_checkout
+test -f $destination_pr_json
+test -f $origin_pr_json
+
+date +%s > $destination_checkout/last
diff --git a/tests/run.sh b/tests/run.sh
index fcaef1a..264eae2 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -51,6 +51,12 @@ function close_pull_request() {
     done
 }
 
+function merge_pull_request() {
+    forgejo-curl.sh api_json ${options[url]}/api/v1/repos/user1/originrepo/pulls | jq --raw-output '.[] | .number' | while read pr ; do
+	forgejo-curl.sh api_json --data-raw '{"Do":"merge"}' ${options[url]}/api/v1/repos/user1/originrepo/pulls/$pr/merge
+    done
+}
+
 function create_pull_request() {
     forgejo-curl.sh api_json ${options[url]}/api/v1/repos/user1/originrepo/pulls | jq --raw-output '.[] | .number' | while read pr ; do
 	forgejo-curl.sh api_json -X DELETE ${options[url]}/api/v1/repos/user1/originrepo/issues/$pr
@@ -96,12 +102,20 @@ function run() {
 
     push_self
 
+    #
+    # create & close
+    #
     create_pull_request
-
+    wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
+    close_pull_request
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
 
-    close_pull_request
-
+    #
+    # create & merge
+    #
+    create_pull_request
+    wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
+    merge_pull_request
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
 }