diff --git a/src/vs/workbench/contrib/chat/browser/chatWidget.ts b/src/vs/workbench/contrib/chat/browser/chatWidget.ts
index 9cec594ee84..7bf9608bd92 100644
--- a/src/vs/workbench/contrib/chat/browser/chatWidget.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatWidget.ts
@@ -386,7 +386,7 @@ export class ChatWidget extends Disposable implements IChatWidget {
 					const responses = this.viewModel?.getItems().filter(isResponseVM);
 					const lastResponse = responses?.[responses.length - 1];
 					if (lastResponse) {
-						const errorDetails = lastResponse.errorDetails ? ` ${lastResponse.errorDetails}` : '';
+						const errorDetails = lastResponse.errorDetails ? ` ${lastResponse.errorDetails.message}` : '';
 						alert(lastResponse.response.value + errorDetails);
 					}
 				});