diff --git a/git_cl.py b/git_cl.py
index 756b683e3..43be2313f 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -2704,8 +2704,8 @@ class _GerritChangelistImpl(_ChangelistCodereviewBase):
     self._detail_cache.setdefault(issue, []).append((frozenset(options), data))
     return data
 
-  def _GetChangeCommit(self, issue=None):
-    issue = issue or self.GetIssue()
+  def _GetChangeCommit(self):
+    issue = self.GetIssue()
     assert issue, 'issue is required to query Gerrit'
     try:
       data = gerrit_util.GetChangeCommit(self._GetGerritHost(), str(issue))