diff --git a/frontend/src/lib/types.ts b/frontend/src/lib/types.ts
index 14686e5..8034d57 100644
--- a/frontend/src/lib/types.ts
+++ b/frontend/src/lib/types.ts
@@ -259,10 +259,15 @@ export interface FundRecord {
   updated_at: string;
 }
 
+export interface FundCategoryAmount {
+  category: string;
+  amount: number;
+}
+
 export interface FundStatistics {
   total_income: number;
   total_expense: number;
   balance: number;
-  income_by_category: Record<string, number>;
-  expense_by_category: Record<string, number>;
+  income_by_category: FundCategoryAmount[];
+  expense_by_category: FundCategoryAmount[];
 }