diff --git a/packages/a2a-server/src/agent/task.ts b/packages/a2a-server/src/agent/task.ts
index 12f58be8b9..35299b11c1 100644
--- a/packages/a2a-server/src/agent/task.ts
+++ b/packages/a2a-server/src/agent/task.ts
@@ -658,7 +658,7 @@ export class Task {
           errorMessage,
         );
 
-        let errMessage = 'Unknown error from LLM stream';
+        let errMessage = `Unknown error from LLM stream: ${JSON.stringify(event)}`;
         if (errorEvent.value) {
           errMessage = parseAndFormatApiError(errorEvent.value);
         }