diff --git a/src/types/chartTypes.ts b/src/types/chartTypes.ts
index 469d4ca..56aa391 100644
--- a/src/types/chartTypes.ts
+++ b/src/types/chartTypes.ts
@@ -7,6 +7,7 @@ export type CategoricalChartDataType = CategoricalChartDataItem[];
 export interface CategoricalChartDataItem {
   x: string;
   y: number;
+  id?: string;
 }
 
 export type TooltipPayload = TooltipPayloadItem[];