diff --git a/kor/prompts.py b/kor/prompts.py
index 72d0229..e7a797d 100644
--- a/kor/prompts.py
+++ b/kor/prompts.py
@@ -105,7 +105,7 @@ def to_messages(self, text: str) -> List[BaseMessage]:
         """Format the template to chat messages."""
         instruction_segment = self.format_instruction_segment(self.node)
 
-        messages: List[BaseMessage] = [SystemMessage(content=instruction_segment)]
+        messages: List[BaseMessage] = [SystemMessage(content=instruction_segment, additional_kwargs={"__openai_role__": "developer"})]
         encoded_examples = self.generate_encoded_examples(self.node)
 
         for example_input, example_output in encoded_examples: