diff --git a/types/slickgrid/index.d.ts b/types/slickgrid/index.d.ts
index d3b30ba74f..3af16c7abd 100644
--- a/types/slickgrid/index.d.ts
+++ b/types/slickgrid/index.d.ts
@@ -1623,7 +1623,7 @@ declare namespace Slick {
 			public getRowById(id: string): number;
 			public getItemById(id: any): T;
 			public getItemByIdx(idx: number): T;
-			public mapRowsToIds(rowArray: T[]): string[];
+			public mapRowsToIds(rowArray: number[]): string[];
 			public setRefreshHints(hints: RefreshHints): void;
 			public setFilterArgs(args: any): void;
 			public refresh(): void;