diff --git a/s3tests/functional/test_s3.py b/s3tests/functional/test_s3.py
index 9e7cedc..d03c9f6 100644
--- a/s3tests/functional/test_s3.py
+++ b/s3tests/functional/test_s3.py
@@ -6055,7 +6055,7 @@ def test_multipart_resend_first_finishes_last():
         lambda: counter.inc()
         )
     mp.upload_part_from_file(fp_dryrun, 1)
-    mp.complete_upload
+    mp.complete_upload()
 
     bucket.delete_key(key_name)