diff --git a/axe.d.ts b/axe.d.ts
index cd78b82ca8..852817f6ac 100644
--- a/axe.d.ts
+++ b/axe.d.ts
@@ -83,8 +83,8 @@ declare module axe {
 	}
 	interface Check {
 		id: string,
-		evaluate: Function,
-		after?: Function,
+		evaluate: Function | string,
+		after?: Function | string,
 		options?: any,
 		matches?: string,
 		enabled?: boolean