diff --git a/types/kendo-ui/index.d.ts b/types/kendo-ui/index.d.ts
index 5da967f60b..7f4c865313 100644
--- a/types/kendo-ui/index.d.ts
+++ b/types/kendo-ui/index.d.ts
@@ -1848,7 +1848,7 @@ declare namespace kendo.ui {
         dates?: any;
         depth?: string;
         disableDates?: any|Function;
-        footer?: boolean|string|Function;
+        footer?: false | string | Function;
         format?: string;
         max?: Date;
         messages?: CalendarMessages;