.prop(propertyName) returns a string

jquery/jquery.d.ts

@@ -378,7 +378,7 @@ interface JQuery {
     html(htmlString: string): JQuery;
     html(htmlContent: (index: number, oldhtml: string) => string): JQuery;
 
-    prop(propertyName: string): any;
+    prop(propertyName: string): string;
     prop(propertyName: string, value: any): JQuery;
     prop(map: any): JQuery;
     prop(propertyName: string, func: (index: any, oldPropertyValue: any) => any): JQuery;