diff --git a/azure/durable_functions/models/DurableOrchestrationClient.py b/azure/durable_functions/models/DurableOrchestrationClient.py
index 6b5630a2..6b473c2c 100644
--- a/azure/durable_functions/models/DurableOrchestrationClient.py
+++ b/azure/durable_functions/models/DurableOrchestrationClient.py
@@ -437,7 +437,7 @@ async def terminate(self, instance_id: str, reason: str) -> None:
         switch_statement = {
             202: lambda: None,  # instance in progress
             410: lambda: None,  # instance failed or terminated
-            404: lambda: lambda: f"No instance with ID '{instance_id}' found.",
+            404: lambda: f"No instance with ID '{instance_id}' found.",
         }
 
         has_error_message = switch_statement.get(