diff --git a/src/state.ts b/src/state.ts
index 38865a1..0105822 100644
--- a/src/state.ts
+++ b/src/state.ts
@@ -12,7 +12,7 @@ export const isState = (obj: any): obj is State<any> => {
 export interface State<T> {
   get(): T;
   set(v: T): void;
-  sub(fn: Listener): Unsubscribe;
+  sub(fn: Listener, fire?: boolean): Unsubscribe;
 }
 
 export function createState<T>(initial: T): State<T> {