diff --git a/src/service/clmcservice/__init__.py b/src/service/clmcservice/__init__.py
index 70c6e76cad9a94cfca999f2b6f54ab717627c2b8..3d56991b194b5c23f742f7205d35fa003fa60489 100644
--- a/src/service/clmcservice/__init__.py
+++ b/src/service/clmcservice/__init__.py
@@ -60,6 +60,8 @@ def main(global_config, **settings):
 
     config = Configurator(settings=settings)
 
+    config.add_tween('clmcservice.tweens.accept_header_tween_factory')
+
     # add routes of the WHOAMI API
     config.add_route('whoami_endpoints', '/whoami/endpoints')
     config.add_route('whoami_endpoints_instance', 'whoami/endpoints/instance')
diff --git a/src/service/clmcservice/tweens.py b/src/service/clmcservice/tweens.py
new file mode 100644
index 0000000000000000000000000000000000000000..a0f9eba9b5a7b4ef5298d32a089c410bb1d31c21
--- /dev/null
+++ b/src/service/clmcservice/tweens.py
@@ -0,0 +1,36 @@
+#!/usr/bin/python3
+"""
+// © University of Southampton IT Innovation Centre, 2018
+//
+// Copyright in this software belongs to University of Southampton
+// IT Innovation Centre of Gamma House, Enterprise Road,
+// Chilworth Science Park, Southampton, SO16 7NS, UK.
+//
+// This software may not be used, sold, licensed, transferred, copied
+// or reproduced in whole or in part in any manner or form or in or
+// on any media by any person other than in accordance with the terms
+// of the Licence Agreement supplied with the software, or otherwise
+// without the prior written consent of the copyright owners.
+//
+// This software is distributed WITHOUT ANY WARRANTY, without even the
+// implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+// PURPOSE, except where stated in the Licence Agreement supplied with
+// the software.
+//
+//      Created By :            Nikolay Stanchev
+//      Created Date :          02-11-2018
+//      Created for Project :   FLAME
+"""
+
+
+def accept_header_tween_factory(handler, registry):
+    """
+    Since clmc-service is currently based on JSON only, make sure an application/json header is passed with the request
+    """
+
+    def accept_header_tween(request):
+        request.accept = 'application/json'
+        response = handler(request)
+        return response
+
+    return accept_header_tween