diff --git a/tests/core/fake_device_module.py b/tests/core/fake_device_module.py
index cf4fa262a..3a8914d6b 100644
--- a/tests/core/fake_device_module.py
+++ b/tests/core/fake_device_module.py
@@ -2,10 +2,6 @@
 
 from ophyd import EpicsMotor
 
-FOO = NonCallableMock()
-BAR = NonCallableMock()
-BAR.__name__ = "BAR"
-
 
 def fake_motor_bundle_b(
     fake_motor_x: EpicsMotor,
@@ -33,3 +29,9 @@ def _mock_with_name(name: str) -> MagicMock:
     mock = MagicMock()
     mock.name = name
     return mock
+
+
+FOO = NonCallableMock()
+BAR = NonCallableMock()
+BAR.__name__ = "BAR"
+BAR.__module__ = fake_motor_bundle_a.__module__
diff --git a/tests/service/test_runner.py b/tests/service/test_runner.py
index 28e8b8d39..7d39fb0d1 100644
--- a/tests/service/test_runner.py
+++ b/tests/service/test_runner.py
@@ -131,6 +131,6 @@ def test_clear_message_for_invalid_function(started_runner: WorkerDispatcher):
 
     with pytest.raises(
         RpcError,
-        match="BAR: No such function in subprocess API",
+        match="BAR: Object in subprocess is not a function",
     ):
         started_runner.run(BAR)