diff --git a/listener/app.py b/listener/app.py
index cd0ba43..c5ae779 100644
--- a/listener/app.py
+++ b/listener/app.py
@@ -64,7 +64,7 @@ def _get_coordination(channel, thread_ts):
 def _dispatch_conversation(text, thread_ts, channel, say, is_dm):
     placeholder_ts = None
     if is_dm:
-        result = say(text="Thinking...", thread_ts=thread_ts)
+        result = say(text="Thinking...")
         placeholder_ts = result["ts"]
 
     lambda_client.invoke(
@@ -143,7 +143,7 @@ def handle_message(event, say):
     if not text:
         return
 
-    thread_ts = event.get("thread_ts") or event["ts"]
+    thread_ts = None
     _dispatch_conversation(text, thread_ts, event["channel"], say, is_dm=True)