diff --git a/packages/exchange/src/exchange/moderators/summarizer.py b/packages/exchange/src/exchange/moderators/summarizer.py
index a7bb1b0f..7a90ed04 100644
--- a/packages/exchange/src/exchange/moderators/summarizer.py
+++ b/packages/exchange/src/exchange/moderators/summarizer.py
@@ -23,7 +23,7 @@ class ContextSummarizer(ContextTruncate):
         summarizer_exchange = exchange.replace(
             system=Message.load("summarizer.jinja").text,
             moderator=PassiveModerator(),
-            model=self.model,
+            model=self.model if self.model else exchange.model,
             messages=messages_to_summarize,
             checkpoint_data=CheckpointData(),
         )