diff --git a/examples/agent_browser/browser_agent.py b/examples/agent_browser/browser_agent.py
index 05a237734c..ebf4d1c8ac 100644
--- a/examples/agent_browser/browser_agent.py
+++ b/examples/agent_browser/browser_agent.py
@@ -322,7 +322,7 @@ async def _memory_summarizing(self) -> None:
         )
 
         # Format the prompt for the model
-        prompt = self.formatter.format(
+        prompt = await self.formatter.format(
             msgs=[
                 Msg("system", self.sys_prompt, "system"),
                 *memory_msgs,