diff --git a/sotopia/messages/message_classes.py b/sotopia/messages/message_classes.py
index dc07e1be4..9176283f3 100644
--- a/sotopia/messages/message_classes.py
+++ b/sotopia/messages/message_classes.py
@@ -327,7 +327,11 @@ def split_by_turn(self, input_string: str) -> list[str]:
         dialogues[-1] = "\n".join(
             dialogues[-1].split("\n")[:2]
         )  # Discard further input in the last turn
-        # print("Dialogues: ", dialogues)
+
+        for dialogue in dialogues:
+            # TODO this is current workaround for the issue of multiple agents in one turn
+            if len(dialogue.split("\n")) >= 3:
+                raise ValueError("Only one agent can act per turn.")
         return dialogues
 
     @staticmethod