diff --git a/skillagent/skillengine.py b/skillagent/skillengine.py
index a219f86..0ecc035 100644
--- a/skillagent/skillengine.py
+++ b/skillagent/skillengine.py
@@ -180,7 +180,7 @@ class IndustrialSkillEngine:
 		
 		return base_content
 
-	async def reference(self, user_prompt:str, context: str=None, is_retry: boolean=False):
+	async def reference(self, user_prompt:str, context: str=None, is_retry: bool=False):
 		f = partial(self.run, user_prompt, context=context, is_retry=is_retry)
 		background_coro(f)
 		while True: