diff --git a/services/pull/patch.go b/services/pull/patch.go
index c5befe39d6d..ef7c366f062 100644
--- a/services/pull/patch.go
+++ b/services/pull/patch.go
@@ -366,7 +366,7 @@ func checkConflicts(ctx context.Context, pr *issues_model.PullRequest, gitRepo *
 		_ = util.Remove(tmpPatchFile.Name())
 	}()
 
-	if err := gitRepo.GetDiffBinary(pr.MergeBase+"..tracking", tmpPatchFile); err != nil {
+	if err := gitRepo.GetDiffBinary(pr.MergeBase+"...tracking", tmpPatchFile); err != nil {
 		tmpPatchFile.Close()
 		log.Error("Unable to get patch file from %s to %s in %s Error: %v", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)
 		return false, fmt.Errorf("unable to get patch file from %s to %s in %s Error: %w", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)