diff --git a/src/commercetools/testing/__init__.py b/src/commercetools/testing/__init__.py
index f7d31816..067189a5 100644
--- a/src/commercetools/testing/__init__.py
+++ b/src/commercetools/testing/__init__.py
@@ -113,7 +113,7 @@ def register(self, adapter):
 
 @contextmanager
 def backend_mocker(*args, **kwargs):
-    with requests_mock.Mocker(real_http=True) as m:
+    with requests_mock.Mocker(real_http=True, case_sensitive=True) as m:
         repo = BackendRepository()
         repo.register(m)
         yield repo
diff --git a/src/commercetools/testing/server.py b/src/commercetools/testing/server.py
index 4a708c5b..3edf49cb 100644
--- a/src/commercetools/testing/server.py
+++ b/src/commercetools/testing/server.py
@@ -39,7 +39,7 @@ def __init__(self, repository=None):
 
     def __call__(self, environ, start_response):
         request = self._create_request(environ)
-        request_mock = _RequestObjectProxy(request.prepare())
+        request_mock = _RequestObjectProxy(request.prepare(), case_sensitive=True)
 
         if request_mock.body is None:
             request_mock.body = ""
diff --git a/tests/test_mock_server.py b/tests/test_mock_server.py
index cd49572d..0fc0c3e9 100644
--- a/tests/test_mock_server.py
+++ b/tests/test_mock_server.py
@@ -1,13 +1,19 @@
-import pytest
+import os
+
 import requests
 
 from commercetools import Client
-from commercetools.types import LocalizedString, ProductDraft
+from commercetools.types import (
+    ChannelDraft,
+    ChannelResourceIdentifier,
+    ChannelRoleEnum,
+    LocalizedString,
+    ProductDraft,
+    StoreDraft,
+)
 
 
 def test_http_server(commercetools_client, commercetools_http_server):
-    import os
-
     os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
 
     client = Client(
@@ -30,3 +36,38 @@ def test_http_server(commercetools_client, commercetools_http_server):
     assert response.status_code == 200, response.text
     data = response.json()
     assert data["masterData"]["staged"]["name"]["nl"] == "Testje"
+
+
+def test_http_server_expanding(commercetools_client, commercetools_http_server):
+    os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"
+
+    client = Client(
+        project_key="unittest",
+        client_id="client-id",
+        client_secret="client-secret",
+        scope=[],
+        url=commercetools_http_server.api_url,
+        token_url=f"{commercetools_http_server.api_url}/oauth/token",
+    )
+
+    client.channels.create(
+        ChannelDraft(key="FOO", roles=[ChannelRoleEnum.PRODUCT_DISTRIBUTION])
+    )
+
+    store = client.stores.create(
+        StoreDraft(
+            key="FOO", distribution_channels=[ChannelResourceIdentifier(key="FOO")]
+        )
+    )
+
+    url = commercetools_http_server.api_url + f"/unittest/stores/{store.id}"
+    response = requests.get(
+        url,
+        params={"expand": "distributionChannels[*]"},
+        headers={"Authorization": "Bearer token"},
+    )
+
+    assert response.status_code == 200, response.text
+    data = response.json()
+
+    assert data["distributionChannels"][0]["obj"]["key"] == "FOO"