diff --git a/test-requirements.txt b/test-requirements.txt
index dfc0d47..1f61c24 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,6 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
+debtcollector>=1.2.0 # Apache-2.0
 hacking>=3.2
 stestr>=1.0.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
diff --git a/watcher_tempest_plugin/tests/client_functional/__init__.py b/watcher_tempest_plugin/tests/client_functional/__init__.py
index e69de29..efd1c93 100644
--- a/watcher_tempest_plugin/tests/client_functional/__init__.py
+++ b/watcher_tempest_plugin/tests/client_functional/__init__.py
@@ -0,0 +1,30 @@
+# -*- encoding: utf-8 -*-
+# Copyright (c) 2025 Red Hat
+#
+# 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.
+from debtcollector import removals
+import warnings
+
+warnings.simplefilter("once", DeprecationWarning)
+removals.removed_module(
+    __name__,
+    replacement="watcherclient.tests.client_functional",
+    removal_version="2026.1",
+    message=(
+        "The 'watcher_tempest_plugin.tests.client_functional' module is "
+        "deprecated and will be removed in version 2026.1. "
+        "We recommend using watcherclient.tests.client_functional for "
+        "running functional tests. "
+    )
+)