diff --git a/pyproject.toml b/pyproject.toml
index 439cf9c..787831d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,3 +12,8 @@ requires = [
 ]
 description-file = "README.md"
 requires-python = ">=3.4"
+
+[tool.flit.metadata.requires-extra]
+test = [
+    "responses"
+]
diff --git a/tests/test_simple.py b/tests/test_simple.py
index 9d45f4f..43a369b 100644
--- a/tests/test_simple.py
+++ b/tests/test_simple.py
@@ -1,2 +1,23 @@
-def test_simple():
-    assert True
+import unittest
+import wideq
+import responses
+import json
+
+
+class SimpleTest(unittest.TestCase):
+    @responses.activate
+    def test_gateway_info(self):
+        responses.add(
+            responses.POST,
+            'https://kic.lgthinq.com:46030/api/common/gatewayUriList',
+            json={'lgedmRoot': 'foo'},
+        )
+
+        data = wideq.gateway_info('COUNTRY', 'LANGUAGE')
+        self.assertEqual(data, 'foo')
+
+        self.assertEqual(len(responses.calls), 1)
+        self.assertEqual(
+            json.loads(responses.calls[0].request.body),
+            {'lgedmRoot': {'countryCode': 'COUNTRY', 'langCode': 'LANGUAGE'}},
+        )
diff --git a/tox.ini b/tox.ini
index 405ccff..4c9ba80 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,6 +3,7 @@ envlist = py34,py35,py36,py37,flake8,coverage
 isolated_build = True
 
 [testenv]
+extras = test
 commands =
     python -m unittest {posargs} discover -s tests