diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index ccfdd4b5..6ae8ad38 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -10,6 +10,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
+        with:
+          repository: eclipse/paho.mqtt.testing
+          ref: a4dc694010217b291ee78ee13a6d1db812f9babd
+          path: paho.mqtt.testing
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python }}
diff --git a/README.rst b/README.rst
index f36c9a50..c80e6854 100644
--- a/README.rst
+++ b/README.rst
@@ -72,6 +72,8 @@ Once you have the code, it can be installed from your repository as well:
 To perform all test (including MQTT v5 test), you also need to clone paho.mqtt.testing in paho.mqtt.python folder::
 
     git clone https://github.com/eclipse/paho.mqtt.testing.git
+    cd paho.mqtt.testing
+    git checkout a4dc694010217b291ee78ee13a6d1db812f9babd
 
 Known limitations
 -----------------
diff --git a/tests/test_mqttv5.py b/tests/test_mqttv5.py
index 7c5cb464..e360491f 100644
--- a/tests/test_mqttv5.py
+++ b/tests/test_mqttv5.py
@@ -23,6 +23,7 @@
 import time
 import traceback
 import unittest
+import unittest.mock
 
 import paho.mqtt
 import paho.mqtt.client
@@ -167,18 +168,22 @@ def setUpClass(cls):
         except ImportError:
             raise unittest.SkipTest("paho.mqtt.testing not present.")
 
-        cls._test_broker = threading.Thread(
-            target=mqtt.brokers.run,
-            kwargs={
-                "config": ["listener 0"],
-            },
-        )
-        cls._test_broker.daemon = True
-        cls._test_broker.start()
-        # Wait a bit for TCP server to bind to an address
-        time.sleep(0.5)
-        # Hack to find the port used by the test broker...
-        cls._test_broker_port = mqtt.brokers.listeners.TCPListeners.server.socket.getsockname()[1]
+        # Hack: we need to patch `signal.signal()` because `mqtt.brokers.run()`
+        #       calls it to set up a signal handler; however, that won't work
+        #       from a thread...
+        with unittest.mock.patch("signal.signal", unittest.mock.MagicMock()):
+            cls._test_broker = threading.Thread(
+                target=mqtt.brokers.run,
+                kwargs={
+                    "config": ["listener 0"],
+                },
+            )
+            cls._test_broker.daemon = True
+            cls._test_broker.start()
+            # Wait a bit for TCP server to bind to an address
+            time.sleep(0.5)
+            # Hack to find the port used by the test broker...
+            cls._test_broker_port = mqtt.brokers.listeners.TCPListeners.server.socket.getsockname()[1]
         setData()
         cleanup(cls._test_broker_port)