diff --git a/node-schedule/node-schedule.d.ts b/node-schedule/node-schedule.d.ts
index ca1dcd094..e1ff005df 100644
--- a/node-schedule/node-schedule.d.ts
+++ b/node-schedule/node-schedule.d.ts
@@ -195,5 +195,5 @@ declare module "node-schedule" {
      * @param {RecurrenceRule} rule The rule.
      * @param {Function} callback The callback.
      */
-    export function scheduleJob(rule: RecurrenceRule|Date|string, callback: Function);
+    export function scheduleJob(rule: RecurrenceRule|Date|string, callback: Function): void;
 }