diff --git a/storage/cloud.py b/storage/cloud.py
index e0a8e35ed..de4e22691 100644
--- a/storage/cloud.py
+++ b/storage/cloud.py
@@ -348,7 +348,7 @@ class _CloudStorage(BaseStorageV2):
           logger.exception(msg, chunk.path, final_path)
 
   @staticmethod
-  def _complete_s3_multipart_upload(self, mpu, path):
+  def _complete_s3_multipart_upload(mpu, path):
     # Note: Sometimes Amazon S3 simply raises an internal error when trying to complete a
     # multipart upload. The recommendation is to simply try calling complete_upload again.
     for remaining_retries in range(3, -1, -1):