diff --git a/exasol_integration_test_docker_environment/lib/base/base_task.py b/exasol_integration_test_docker_environment/lib/base/base_task.py
index 028ef0f5f..42ff817cb 100644
--- a/exasol_integration_test_docker_environment/lib/base/base_task.py
+++ b/exasol_integration_test_docker_environment/lib/base/base_task.py
@@ -3,7 +3,7 @@
 import logging
 import shutil
 from pathlib import Path
-from typing import Dict, List, Generator, Any, Union, Set, Optional
+from typing import Dict, List, Generator, Any, Union, Set
 
 import luigi
 import six
diff --git a/exasol_integration_test_docker_environment/lib/test_environment/spawn_test_container.py b/exasol_integration_test_docker_environment/lib/test_environment/spawn_test_container.py
index 658fb7cbf..e182c0682 100644
--- a/exasol_integration_test_docker_environment/lib/test_environment/spawn_test_container.py
+++ b/exasol_integration_test_docker_environment/lib/test_environment/spawn_test_container.py
@@ -1,4 +1,4 @@
-from typing import List
+from typing import List, Optional
 
 import luigi
 import netaddr
diff --git a/test/integration/conftest.py b/test/integration/conftest.py
index 72d5b42d5..bb2d23870 100644
--- a/test/integration/conftest.py
+++ b/test/integration/conftest.py
@@ -1,6 +1,5 @@
 import contextlib
 import io
-from contextlib import _GeneratorContextManager
 
 import pytest