diff --git a/01_ai_agents_first/18_guardrails/saftey_rails/main.py b/01_ai_agents_first/18_guardrails/saftey_rails/main.py
index 2db7c980..47c37b6c 100644
--- a/01_ai_agents_first/18_guardrails/saftey_rails/main.py
+++ b/01_ai_agents_first/18_guardrails/saftey_rails/main.py
@@ -25,7 +25,7 @@
 
 class WeatherSanitizer(BaseModel):
     weather_related: bool
-    reason: str | None = None
+    reason: str
 
 weather_sanitizer = Agent(
     name="WeatherSanitizer",
@@ -66,4 +66,4 @@ def weather_response_checker(ctx: RunContextWrapper, agent: Agent, output: Any):
 except InputGuardrailTripwireTriggered as e:
     print("Alert: Guardrail input tripwire was triggered!")
 except OutputGuardrailTripwireTriggered as e:
-    print("Alert: Guardrail output tripwire was triggered!")
\ No newline at end of file
+    print("Alert: Guardrail output tripwire was triggered!")