diff --git a/pr-review/main.go b/pr-review/main.go
index b2090bc..1bc9a5a 100644
--- a/pr-review/main.go
+++ b/pr-review/main.go
@@ -59,7 +59,7 @@ func processPullRequestSync(h *common.RequestHandler) error {
 	h.Log("associated pr: %v", prjPr)
 
 	h.GitExec("", "clone", "--branch", prjPr.Head.Name, "--depth", "1", prjPr.Head.Repo.SSHURL, common.DefaultGitPrj)
-	commitId, ok := h.GitSubmoduleCommitId(common.DefaultGitPrj, req.Repository.Name, prjPr.Head.Ref)
+	commitId, ok := h.GitSubmoduleCommitId(common.DefaultGitPrj, req.Repository.Name, prjPr.Head.Sha)
 
 	if !ok {
 		return fmt.Errorf("Cannot fetch submodule commit id in prjgit for '%s'", req.Repository.Name)