diff --git a/functional-samples/ai.gemini-on-device-summarization/sidepanel/index.js b/functional-samples/ai.gemini-on-device-summarization/sidepanel/index.js
index 0342bf5af6..242b8c04d1 100644
--- a/functional-samples/ai.gemini-on-device-summarization/sidepanel/index.js
+++ b/functional-samples/ai.gemini-on-device-summarization/sidepanel/index.js
@@ -56,8 +56,8 @@ async function generateSummary(text) {
 }
 
 async function createSummarizationSession(downloadProgressCallback) {
-  if (!window.ai.summarizer) {
-    throw new Error('AI Summarization is not supported');
+  if (!window.ai || !window.ai.summarizer) {
+    throw new Error('AI Summarization is not supported in this browser');
   }
   const canSummarize = await window.ai.summarizer.capabilities();
   if (canSummarize.available === 'no') {