diff --git a/src/main/runtime/runtime-rpc/runtime-rpc-long-poll.ts b/src/main/runtime/runtime-rpc/runtime-rpc-long-poll.ts
index 15fc3af44f2..c1ddeb78a6e 100644
--- a/src/main/runtime/runtime-rpc/runtime-rpc-long-poll.ts
+++ b/src/main/runtime/runtime-rpc/runtime-rpc-long-poll.ts
@@ -32,7 +32,8 @@ export function classifyRuntimeLongPoll(request: RpcRequest): RuntimeLongPollCla
     (request.method === 'agent.launch' || request.method === 'agent.launchReplay') &&
     typeof request.params === 'object' &&
     request.params !== null &&
-    (request.params as { prompt?: unknown }).prompt !== undefined
+    'prompt' in request.params &&
+    request.params.prompt !== undefined
   ) {
     return 'wait'
   }