diff --git a/SAS/TMSS/client/lib/tmss_http_rest_client.py b/SAS/TMSS/client/lib/tmss_http_rest_client.py
index 885ccc9565d7b3397d12a71ed630853d7940fc97..5b89c36049361afc1269ad2002a36f642c3ac0af 100644
--- a/SAS/TMSS/client/lib/tmss_http_rest_client.py
+++ b/SAS/TMSS/client/lib/tmss_http_rest_client.py
@@ -63,6 +63,7 @@ class TMSSsession(object):
         '''open the request session and login'''
         self.session.__enter__()
         self.session.verify = False
+        self.session.headers['Accept'] = 'application/json'
 
         if self.authentication_method == self.OPENID:
             # get authentication page of OIDC through TMSS redirect
@@ -162,9 +163,6 @@ class TMSSsession(object):
 
     def get_url_as_json_object(self, full_url: str, params={}) -> object:
         '''get resource at the given full url (including http://<base_url>, interpret it as json, and return it as as native object (usually a dict or a list of dicts)'''
-        if "format=json" not in full_url or params.get("format") != "json":
-            params['format'] ='json'
-
         response = self.session.get(url=full_url, params=params)
         logger.info("%s %s %s on %s", response.request.method.upper(), response.status_code, responses.get(response.status_code), response.request.url)