diff --git a/types/yandex-maps/index.d.ts b/types/yandex-maps/index.d.ts
index e717fd5a58..94806b9254 100644
--- a/types/yandex-maps/index.d.ts
+++ b/types/yandex-maps/index.d.ts
@@ -3038,7 +3038,7 @@ declare namespace ymaps {
 	}
 	class Monitor {
     	constructor(dataManager: IDataManager | IOptionManager);
-   		add(name: string[] | string, changeCallback: (event: (object | IEvent)) => void, context: any = null, params: any = null): Monitor;
+   		add(name: string[] | string, changeCallback: (event: (object | IEvent)) => void, context?: any, params?: any): Monitor;
     	forceChange(): Monitor;
     	get(name: string): any;
     	remove(name: string): Monitor;