diff --git a/models/pull.go b/models/pull.go
index 5c54a2268a..45fe852e9f 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -1010,6 +1010,7 @@ func (pr *PullRequest) PushToBaseRepo() (err error) {
 	if err = git.Push(headRepoPath, git.PushOptions{
 		Remote: tmpRemoteName,
 		Branch: fmt.Sprintf("%s:%s", pr.HeadBranch, headFile),
+		Force:  true,
 	}); err != nil {
 		return fmt.Errorf("Push: %v", err)
 	}