diff --git a/git/repo/base.py b/git/repo/base.py
index 96c78df56..67ccb12ba 100644
--- a/git/repo/base.py
+++ b/git/repo/base.py
@@ -824,7 +824,7 @@ def merge_base(self, *rev: TBD, **kwargs: Any) -> List[Commit]:
 
         return res
 
-    def is_ancestor(self, ancestor_rev: Commit, rev: Commit) -> bool:
+    def is_ancestor(self, ancestor_rev: TBD, rev: TBD) -> bool:
         """Check if a commit is an ancestor of another.
 
         :param ancestor_rev: