diff --git a/src/openflexure_microscope_server/things/stage/sangaboard.py b/src/openflexure_microscope_server/things/stage/sangaboard.py
index acfa7bff..84d75e92 100644
--- a/src/openflexure_microscope_server/things/stage/sangaboard.py
+++ b/src/openflexure_microscope_server/things/stage/sangaboard.py
@@ -44,12 +44,12 @@ class SangaboardThing(BaseStage):
         """
         self.sangaboard_kwargs = copy(kwargs)
         self.sangaboard_kwargs["port"] = port
+        self._sangaboard_lock = threading.RLock()
         super().__init__(**kwargs)
 
     def __enter__(self) -> None:
         """Connect to the sangaboard when the Thing context manager is opened."""
         self._sangaboard = sangaboard.Sangaboard(**self.sangaboard_kwargs)
-        self._sangaboard_lock = threading.RLock()
         with self.sangaboard() as sb:
             sb.query("blocking_moves false")
         self.check_firmware()
diff --git a/tests/test_sangaboard.py b/tests/test_sangaboard.py
new file mode 100644
index 00000000..bf1c8394
--- /dev/null
+++ b/tests/test_sangaboard.py
@@ -0,0 +1,20 @@
+"""Tests for the Sangaboard thing."""
+
+import pytest
+
+from openflexure_microscope_server.things.stage.sangaboard import SangaboardThing
+
+
+@pytest.fixture
+def mock_sanga_thing(mocker):
+    """Return a Sangaboard thing with a MagicMock for self._sangaboard."""
+    sanga_thing = SangaboardThing()
+    sanga_thing._sangaboard = mocker.MagicMock()
+    return sanga_thing
+
+
+def test_check_old_firmware(mock_sanga_thing):
+    """Check firmware prior to version 1 throws a Runtime Error."""
+    mock_sanga_thing._sangaboard.firmware_version.return_value = "0.1.1"
+    with pytest.raises(RuntimeError):
+        mock_sanga_thing.check_firmware()