diff --git a/src/components/three/ModelViewer.tsx b/src/components/three/ModelViewer.tsx
index d6b8d6f..1d39073 100644
--- a/src/components/three/ModelViewer.tsx
+++ b/src/components/three/ModelViewer.tsx
@@ -143,6 +143,10 @@ function GLBModel({ sceneModel, isActive }: { sceneModel: SceneModel; isActive:
   const measureMode = useModelStore((s) => s.measureMode);
   const fineTuning = sceneModel.fineTuning;
 
+  // Re-render when calibration state changes (so calQuat resets to identity during the flow).
+  const [, setCalTick] = useState(0);
+  useEffect(() => subscribeCalibration(() => setCalTick(t => t + 1)), []);
+
   const modelInfo = useMemo(() => {
     if (!scene) return { size: new THREE.Vector3(), center: new THREE.Vector3() };
     const box = new THREE.Box3().setFromObject(scene);