diff --git a/README.md b/README.md
index 5a03bbc..099f2ba 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,6 @@
 # LingDocs Pashto Grammar
 
 [![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)
-
 [![Netlify Status](https://api.netlify.com/api/v1/badges/150beb8b-aae1-4cef-a05c-2add5d8904f7/deploy-status)](https://app.netlify.com/sites/pashto-grammar/deploys)
 ![build](https://github.com/lingdocs/grammar.lingdocs.com/actions/workflows/main.yml/badge.svg)
 
diff --git a/src/games/GameCore.tsx b/src/games/GameCore.tsx
index cf8bcb0..db1d3ff 100644
--- a/src/games/GameCore.tsx
+++ b/src/games/GameCore.tsx
@@ -214,7 +214,9 @@ function GameCore<Question>({ inChapter, getQuestion, amount, Display, DisplayCo
         }
     }
     function punish() {
-        navigator.vibrate(errorVibration);
+        if (navigator.vibrate) {
+            navigator.vibrate(errorVibration);
+        }
     }
     function handleResult(done: boolean) {
         const result: AT.TestResult = {