diff --git a/tosfs/core.py b/tosfs/core.py
index eebc8d0..ed1a2e0 100644
--- a/tosfs/core.py
+++ b/tosfs/core.py
@@ -472,7 +472,7 @@ def mkdir(self, path: str, create_parents: bool = True, **kwargs: Any) -> None:
                 raise FileNotFoundError(f"Parent directory {parent} does not exist.")
             else:
                 retryable_func(
-                    self.tos_client.put_object(bucket, key.rstrip("/") + "/"),
+                    lambda: self.tos_client.put_object(bucket, key.rstrip("/") + "/"),
                     max_retry_num=self.max_retry_num,
                 )