diff --git a/src/util.ts b/src/util.ts
index 7f7c558c..4bc0391a 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -84,7 +84,7 @@ export const eventPosition = (e: cg.MouchEvent): cg.NumberPair | undefined => {
   return; // touchend has no position!
 };
 
-export const isRightButton = (e: cg.MouchEvent): boolean => ((e.buttons ?? 0) & 2) === 2;
+export const isRightButton = (e: cg.MouchEvent): boolean => e.button === 2;
 
 export const createEl = (tagName: string, className?: string): HTMLElement => {
   const el = document.createElement(tagName);