diff --git a/rx/rx.binding-lite.d.ts b/rx/rx.binding-lite.d.ts
index f896e260d..b798f342f 100644
--- a/rx/rx.binding-lite.d.ts
+++ b/rx/rx.binding-lite.d.ts
@@ -7,6 +7,7 @@
 
 declare module Rx {
 	export interface BehaviorSubject<T> extends Subject<T> {
+		getValue(): T;
 	}
 
 	interface BehaviorSubjectStatic {