diff --git a/setra_client/client.py b/setra_client/client.py
index ad39b64c9dce0e9a957daf7a4d3acfdc369c4ec8..53595a207a817416bea5bbd2824089177216c3e1 100644
--- a/setra_client/client.py
+++ b/setra_client/client.py
@@ -285,7 +285,7 @@ class SetraClient(object):
         url = self.urls.post_new_batch()
         headers = {'Content-Type': 'application/json'}
         response = self.post(url,
-                             data=batchdata.json(),
+                             data=batchdata.json(exclude_unset=True),
                              headers=headers,
                              return_response=True)
         try: