diff --git a/routers/web/repo/pull.go b/routers/web/repo/pull.go
index fc95bbf240..98b78645dc 100644
--- a/routers/web/repo/pull.go
+++ b/routers/web/repo/pull.go
@@ -1381,7 +1381,7 @@ func CleanUpPullRequest(ctx *context.Context) {
 }
 
 func deleteBranch(ctx *context.Context, pr *issues_model.PullRequest, gitRepo *git.Repository) {
-	fullBranchName := pr.HeadRepo.Owner.Name + "/" + pr.HeadBranch
+	fullBranchName := pr.HeadRepo.FullName() + ":" + pr.HeadBranch
 	if err := repo_service.DeleteBranch(ctx.Doer, pr.HeadRepo, gitRepo, pr.HeadBranch); err != nil {
 		switch {
 		case git.IsErrBranchNotExist(err):
diff --git a/tests/integration/pull_merge_test.go b/tests/integration/pull_merge_test.go
index 9bd430084d..e14f2bbc30 100644
--- a/tests/integration/pull_merge_test.go
+++ b/tests/integration/pull_merge_test.go
@@ -187,7 +187,7 @@ func TestPullCleanUpAfterMerge(t *testing.T) {
 		htmlDoc := NewHTMLParser(t, resp.Body)
 		resultMsg := htmlDoc.doc.Find(".ui.message>p").Text()
 
-		assert.EqualValues(t, "Branch 'user1/feature/test' has been deleted.", resultMsg)
+		assert.EqualValues(t, "Branch 'user1/repo1:feature/test' has been deleted.", resultMsg)
 	})
 }