1 files changed, 4 insertions, 1 deletions
diff --git a/src/client/util/InteractionUtils.tsx b/src/client/util/InteractionUtils.tsx
index 1fe95474c..ad1d1b5de 100644
--- a/src/client/util/InteractionUtils.tsx
+++ b/src/client/util/InteractionUtils.tsx
@@ -63,7 +63,7 @@ export namespace InteractionUtils {
     export function GetMyTargetTouches(mte: InteractionUtils.MultiTouchEvent<React.TouchEvent | TouchEvent>, prevPoints: Map<number, React.Touch>, ignorePen: boolean): React.Touch[] {
         const myTouches = new Array<React.Touch>();
         for (const pt of mte.touches) {
-            if (!ignorePen || (pt.radiusX > 1 && pt.radiusY > 1)) {
+            if (!ignorePen || ((pt as any).radiusX > 1 && (pt as any).radiusY > 1)) {
                 for (const tPt of mte.targetTouches) {
                     if (tPt?.screenX === pt?.screenX && tPt?.screenY === pt?.screenY) {
                         if (pt && prevPoints.has(pt.identifier)) {
@@ -73,6 +73,9 @@ export namespace InteractionUtils {
                 }
             }
         }
+        if (mte.touches.length !== myTouches.length) {
+            throw Error("opo")
+        }
         return myTouches;
     }