diff --git a/keystoneauth1/session.py b/keystoneauth1/session.py
index db01a4de..e4133eda 100644
--- a/keystoneauth1/session.py
+++ b/keystoneauth1/session.py
@@ -155,6 +155,9 @@ def _determine_user_agent():
         # sys.argv is empty, usually the Python interpreter prevents this.
         return None
 
+    if not name:
+        return None
+
     name = os.path.basename(name)
     if name in ignored:
         name = _determine_calling_package()
diff --git a/keystoneauth1/tests/unit/test_session.py b/keystoneauth1/tests/unit/test_session.py
index ccef46fa..39c87d35 100644
--- a/keystoneauth1/tests/unit/test_session.py
+++ b/keystoneauth1/tests/unit/test_session.py
@@ -146,9 +146,11 @@ class SessionTests(utils.TestCase):
         # If sys.argv[0] is an empty string, then doesn't fail.
         with mock.patch.object(sys, 'argv', ['']):
             session = client_session.Session()
-            # NOTE(blk-u): This isn't working right, see bug 1611426
-            self.assertRaises(exceptions.UnknownConnectionError, session.get,
-                              self.TEST_URL)
+            resp = session.get(self.TEST_URL)
+            self.assertTrue(resp.ok)
+            self.assertRequestHeaderEqual(
+                'User-Agent',
+                client_session.DEFAULT_USER_AGENT)
 
     def test_http_session_opts(self):
         session = client_session.Session(cert='cert.pem', timeout=5,