diff --git a/tests/tests_fabric/test_connector.py b/tests/tests_fabric/test_connector.py
index 1e27b31af8403..81a07b71f8f44 100644
--- a/tests/tests_fabric/test_connector.py
+++ b/tests/tests_fabric/test_connector.py
@@ -715,10 +715,16 @@ def test_gpu_accelerator_backend_choice_cuda(*_):
     assert isinstance(connector.accelerator, CUDAAccelerator)
 
 
+class DeviceMock(Mock):
+    def __instancecheck__(self, instance):
+        return True
+
+
 @RunIf(min_torch="1.12")
 @mock.patch("lightning.fabric.accelerators.mps.MPSAccelerator.is_available", return_value=True)
 @mock.patch("lightning.fabric.accelerators.mps._get_all_available_mps_gpus", return_value=[0])
-def test_gpu_accelerator_backend_choice_mps(*_):
+@mock.patch("torch.device", DeviceMock)
+def test_gpu_accelerator_backend_choice_mps(*_: object) -> object:
     connector = _Connector(accelerator="gpu")
     assert connector._accelerator_flag == "mps"
     assert isinstance(connector.accelerator, MPSAccelerator)
@@ -931,10 +937,6 @@ def _mock_interactive():
     assert isinstance(connector.strategy, SingleDeviceStrategy)
     assert connector._devices_flag == [0]
 
-    class DeviceMock(Mock):
-        def __instancecheck__(self, instance):
-            return True
-
     # single TPU
     with no_cuda, no_mps, monkeypatch.context():
         mock_tpu_available(monkeypatch, True)
diff --git a/tests/tests_pytorch/trainer/connectors/test_accelerator_connector.py b/tests/tests_pytorch/trainer/connectors/test_accelerator_connector.py
index 7c5402df9c69b..1dc815920be64 100644
--- a/tests/tests_pytorch/trainer/connectors/test_accelerator_connector.py
+++ b/tests/tests_pytorch/trainer/connectors/test_accelerator_connector.py
@@ -725,7 +725,7 @@ def test_gpu_accelerator_backend_choice_cuda(cuda_count_1):
     assert isinstance(trainer.accelerator, CUDAAccelerator)
 
 
-def test_gpu_accelerator_backend_choice_mps(mps_count_1):
+def test_gpu_accelerator_backend_choice_mps(mps_count_1, cuda_count_0):
     trainer = Trainer(accelerator="gpu")
     assert trainer._accelerator_connector._accelerator_flag == "mps"
     assert isinstance(trainer.accelerator, MPSAccelerator)
@@ -805,6 +805,11 @@ def test_bagua_external_strategy(monkeypatch):
     assert isinstance(trainer.strategy, BaguaStrategy)
 
 
+class DeviceMock(Mock):
+    def __instancecheck__(self, instance):
+        return True
+
+
 @pytest.mark.parametrize("is_interactive", (False, True))
 def test_connector_auto_selection(monkeypatch, is_interactive):
     import lightning.fabric  # avoid breakage with standalone package
@@ -873,10 +878,6 @@ def _mock_tpu_available(value):
     assert isinstance(connector.strategy, SingleDeviceStrategy)
     assert connector._devices_flag == [0]
 
-    class DeviceMock(Mock):
-        def __instancecheck__(self, instance):
-            return True
-
     # single TPU
     with monkeypatch.context():
         mock_cuda_count(monkeypatch, 0)