diff --git a/src/dbscanserving/client/DbscanServingClient.py b/src/dbscanserving/client/DbscanServingClient.py
index 7794115c57f8d1e8d25453c5846de2890d4e588d..be653567a947a9ad2791bd30c1a08eded126f644 100644
--- a/src/dbscanserving/client/DbscanServingClient.py
+++ b/src/dbscanserving/client/DbscanServingClient.py
@@ -66,8 +66,7 @@ class DbscanServingClient:
         response: DetectionResponse = self.stub.Detect(request)
         LOGGER.debug(
             "Detect result with {} cluster indices [{}]".format(
-                len(response.cluster_indices),
-                Counter(response.cluster_indices)
+                len(response.cluster_indices), Counter(response.cluster_indices)
             )
         )
         return response
diff --git a/src/dbscanserving/tests/test_unitary.py b/src/dbscanserving/tests/test_unitary.py
index 5498b184f3c0774a7475b019ef3e18ddd2eb4456..9de9b9c910215791ddeb0f91bc0fe5d09cf2e691 100644
--- a/src/dbscanserving/tests/test_unitary.py
+++ b/src/dbscanserving/tests/test_unitary.py
@@ -13,9 +13,10 @@
 # limitations under the License.
 
 import logging
+import os
 import random
+from unittest.mock import patch
 
-import numpy
 import pytest
 from common.proto.dbscanserving_pb2 import DetectionRequest, DetectionResponse, Sample
 from dbscanserving.client.DbscanServingClient import DbscanServingClient
@@ -40,8 +41,16 @@ def dbscanserving_service():
 
 @pytest.fixture(scope="session")
 def dbscanserving_client():
-    _client = DbscanServingClient(host="127.0.0.1", port=port)
-    yield _client
+    with patch.dict(
+        os.environ,
+        {
+            "DBSCANSERVINGSERVICE_SERVICE_HOST": "127.0.0.1",
+            "DBSCANSERVINGSERVICE_SERVICE_PORT_GRPC": str(port),
+        },
+        clear=True,
+    ):
+        _client = DbscanServingClient()
+        yield _client
     _client.close()