diff --git a/index.d.ts b/index.d.ts
index 53261cb1b..c72c202ae 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,5 +1,6 @@
 export interface ObservableLike {
-	subscribe(observer: (value: any) => void): void;
+	subscribe(observer: (value: unknown) => void): void;
+	[Symbol.observable](): ObservableLike;
 }
 
 export type Constructor = (new (...args: Array<any>) => any);