diff --git a/src/components/three/XRControllerMeasure.tsx b/src/components/three/XRControllerMeasure.tsx
index 56969fd..0adad8d 100644
--- a/src/components/three/XRControllerMeasure.tsx
+++ b/src/components/three/XRControllerMeasure.tsx
@@ -174,14 +174,24 @@ export function XRControllerMeasure() {
 
     if (session && right && !hitTestRequestedRef.current && isAligning) {
       hitTestRequestedRef.current = true;
-      session.requestHitTestSource({ space: right.targetRaySpace })
-        .then((source) => {
-          hitTestSourceRef.current = source;
-        })
-        .catch((err) => {
-          console.error('[XR] Failed to request controller hit test source:', err);
+      const spaceToUse = right.targetRaySpace ?? right.gripSpace;
+      if (spaceToUse) {
+        try {
+          session.requestHitTestSource({ space: spaceToUse })
+            .then((source) => {
+              hitTestSourceRef.current = source;
+            })
+            .catch((err) => {
+              console.error('[XR] Failed to request controller hit test source:', err);
+              hitTestRequestedRef.current = false;
+            });
+        } catch (err) {
+          console.error('[XR] Synchronous error requesting controller hit test source:', err);
           hitTestRequestedRef.current = false;
-        });
+        }
+      } else {
+        hitTestRequestedRef.current = false;
+      }
     }
 
     let realHitPoint: THREE.Vector3 | null = null;