diff --git a/unit_tests/charm_tests/test_tempest.py b/unit_tests/charm_tests/test_tempest.py
new file mode 100644
index 0000000..9c4fc9a
--- /dev/null
+++ b/unit_tests/charm_tests/test_tempest.py
@@ -0,0 +1,66 @@
+# Copyright 2020 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import mock
+import unittest
+
+import zaza.openstack.charm_tests.tempest.setup as tempest_setup
+
+
+class TestTempestSetup(unittest.TestCase):
+    """Test class to encapsulate testing Mysql test utils."""
+
+    def setUp(self):
+        super(TestTempestSetup, self).setUp()
+
+    def test_add_environment_var_config_with_missing_variable(self):
+        ctxt = {}
+        with self.assertRaises(Exception) as context:
+            tempest_setup.add_environment_var_config(ctxt, ['swift'])
+        self.assertEqual(
+            ('Environment variables [TEST_SWIFT_IP] must all be '
+             'set to run this test'),
+            str(context.exception))
+
+    @mock.patch.object(tempest_setup.deployment_env, 'get_deployment_context')
+    def test_add_environment_var_config_with_all_variables(
+            self,
+            get_deployment_context):
+        ctxt = {}
+        get_deployment_context.return_value = {
+            'TEST_GATEWAY': 'test',
+            'TEST_CIDR_EXT': 'test',
+            'TEST_FIP_RANGE': 'test',
+            'TEST_NAMESERVER': 'test',
+            'TEST_CIDR_PRIV': 'test',
+        }
+        tempest_setup.add_environment_var_config(ctxt, ['neutron'])
+        self.assertEqual(ctxt['test_gateway'], 'test')
+
+    @mock.patch.object(tempest_setup.deployment_env, 'get_deployment_context')
+    def test_add_environment_var_config_with_some_variables(
+            self,
+            get_deployment_context):
+        ctxt = {}
+        get_deployment_context.return_value = {
+            'TEST_GATEWAY': 'test',
+            'TEST_NAMESERVER': 'test',
+            'TEST_CIDR_PRIV': 'test',
+        }
+        with self.assertRaises(Exception) as context:
+            tempest_setup.add_environment_var_config(ctxt, ['neutron'])
+        self.assertEqual(
+            ('Environment variables [TEST_CIDR_EXT, TEST_FIP_RANGE] must '
+             'all be set to run this test'),
+            str(context.exception))
diff --git a/zaza/openstack/charm_tests/tempest/setup.py b/zaza/openstack/charm_tests/tempest/setup.py
index e7a1c41..98ea327 100644
--- a/zaza/openstack/charm_tests/tempest/setup.py
+++ b/zaza/openstack/charm_tests/tempest/setup.py
@@ -190,6 +190,7 @@ def add_environment_var_config(ctxt, services):
     :rtype: None
     """
     deploy_env = deployment_env.get_deployment_context()
+    missing_vars = []
     for svc, env_vars in SETUP_ENV_VARS.items():
         if svc in services:
             for var in env_vars:
@@ -197,9 +198,11 @@ def add_environment_var_config(ctxt, services):
                 if value:
                     ctxt[var.lower()] = value
                 else:
-                    raise ValueError(
-                        ("Environment variables {} must all be set to run this"
-                         " test").format(', '.join(env_vars)))
+                    missing_vars.append(var)
+    if missing_vars:
+        raise ValueError(
+            ("Environment variables [{}] must all be set to run this"
+             " test").format(', '.join(missing_vars)))
 
 
 def add_auth_config(ctxt):