diff --git a/keystoneauth1/session.py b/keystoneauth1/session.py
index d0794e93..317324e2 100644
--- a/keystoneauth1/session.py
+++ b/keystoneauth1/session.py
@@ -623,14 +623,14 @@ class Session(object):
             elif self.app_name:
                 agent.append(self.app_name)
 
-            for additional in self.additional_user_agent:
-                agent.append('%s/%s' % additional)
-
             if client_name and client_version:
                 agent.append('%s/%s' % (client_name, client_version))
             elif client_name:
                 agent.append(client_name)
 
+            for additional in self.additional_user_agent:
+                agent.append('%s/%s' % additional)
+
             if not agent:
                 # NOTE(jamielennox): determine_user_agent will return an empty
                 # string on failure so checking for None will ensure it is only
diff --git a/keystoneauth1/tests/unit/test_session.py b/keystoneauth1/tests/unit/test_session.py
index 5aa0ccba..c411f83f 100644
--- a/keystoneauth1/tests/unit/test_session.py
+++ b/keystoneauth1/tests/unit/test_session.py
@@ -1307,7 +1307,7 @@ class AdapterTest(utils.TestCase):
 
         adap.get(url)
 
-        agent = 'ksatest/1.2.3 one/1.1.1 two/2.2.2 testclient/4.5.6'
+        agent = 'ksatest/1.2.3 testclient/4.5.6 one/1.1.1 two/2.2.2'
         self.assertEqual(agent + ' ' + client_session.DEFAULT_USER_AGENT,
                          self.requests_mock.last_request.headers['User-Agent'])