diff --git a/docs/howtos/customizations/metrics/_write_your_own_metric_advanced.md b/docs/howtos/customizations/metrics/_write_your_own_metric_advanced.md
index af4ca8c172..c7ec03a5fc 100644
--- a/docs/howtos/customizations/metrics/_write_your_own_metric_advanced.md
+++ b/docs/howtos/customizations/metrics/_write_your_own_metric_advanced.md
@@ -87,7 +87,7 @@ import typing as t
 class RefusalRate(MetricWithLLM, MultiTurnMetric, SingleTurnMetric):
     name: str = "refusal_rate"
     _required_columns: t.Dict[MetricType, t.Set[str]] = field(
-        default_factory=lambda: {MetricType.SINGLE_TURN: {"response", "reference"}}
+        default_factory=lambda: {MetricType.SINGLE_TURN: {"response", "user_input"}}
     )
     refusal_prompt: PydanticPrompt = RefusalPrompt()