diff --git a/src/openflexure_microscope_server/things/camera/picamera.py b/src/openflexure_microscope_server/things/camera/picamera.py
index 79c19c1f..2afc1d7b 100644
--- a/src/openflexure_microscope_server/things/camera/picamera.py
+++ b/src/openflexure_microscope_server/things/camera/picamera.py
@@ -1097,6 +1097,6 @@ class StreamingPiCamera2(BaseCamera):
     @property
     def thing_state(self) -> Mapping[str, Any]:
         """Update generic camera metadata with Picamera-specific data."""
-        state = super().thing_state
+        state = dict(super().thing_state)
         state["camera_board"] = self._camera_board
         return state