diff --git a/src/pipecat/services/cartesia/tts.py b/src/pipecat/services/cartesia/tts.py
index c0b1fd09e..bc7b1f121 100644
--- a/src/pipecat/services/cartesia/tts.py
+++ b/src/pipecat/services/cartesia/tts.py
@@ -167,7 +167,7 @@ class CartesiaTTSService(AudioContextWordTTSService):
             "output_format": self._settings["output_format"],
             "language": self._settings["language"],
             "add_timestamps": add_timestamps,
-            "use_original_timestamps": True if self.model_name == "sonic-2" else False,
+            "use_original_timestamps": False if self.model_name == "sonic" else True,
         }
         return json.dumps(msg)