diff --git a/boto3utils/s3.py b/boto3utils/s3.py
index e9724c7..7ec54c3 100644
--- a/boto3utils/s3.py
+++ b/boto3utils/s3.py
@@ -94,7 +94,7 @@ def upload_json(self, data, url, extra={}, **kwargs):
         _extra = {
             'ContentType': 'application/json'
         }
-        _extra.update(extra))
+        _extra.update(extra)
         with open(filename, 'w') as f:
             f.write(json.dumps(data))
         try: