diff --git a/knockout.rx/knockout.rx-tests.ts b/knockout.rx/knockout.rx-tests.ts
new file mode 100644
index 0000000000..674e9bb6a4
--- /dev/null
+++ b/knockout.rx/knockout.rx-tests.ts
@@ -0,0 +1,12 @@
+/// <reference path="knockout.rx.d.ts"/>
+
+var ax: Rx.IObservable<number>;
+
+var ao = ax.toKoObservable();
+
+ao(100);
+ao.getSubscriptionsCount();
+
+ao.toObservable();
+ao.toObservable("change");
+ao.toObservable<Error>("error");
\ No newline at end of file
diff --git a/knockout.rx/knockout.rx.d.ts b/knockout.rx/knockout.rx.d.ts
new file mode 100644
index 0000000000..4f44153d8c
--- /dev/null
+++ b/knockout.rx/knockout.rx.d.ts
@@ -0,0 +1,26 @@
+// Type definitions for knockout.rx 0.1
+// Project: https://github.com/Igorbek/knockout.rx
+// Definitions by: Igor Oleinikov <https://github.com/Igorbek>
+
+/// <reference path="../knockout/knockout.d.ts"/>
+/// <reference path="../rx.js/rx.js.d.ts"/>
+
+interface KnockoutSubscribableFunctions<T> {
+	toObservable(event?: string): Rx.IObservable<T>;
+	toObservable<TEvent>(event: string): Rx.IObservable<TEvent>;
+}
+
+interface KnockoutObservableFunctions<T> {
+	toObservableWithReplyLatest(): Rx.IObservable<T>;
+}
+
+interface KnockoutComputedFunctions<T> {
+	toObservableWithReplyLatest(): Rx.IObservable<T>;
+}
+
+declare module Rx {
+	interface IObservable<T> {
+		toKoSubscribable(): KnockoutSubscribable<T>;
+		toKoObservable(initialValue?: T): KnockoutObservable<T>;
+	}
+}
diff --git a/knockout/knockout.d.ts b/knockout/knockout.d.ts
index 63f9938943..c3d6328360 100644
--- a/knockout/knockout.d.ts
+++ b/knockout/knockout.d.ts
@@ -52,10 +52,8 @@ interface KnockoutSubscription {
 }
 
 interface KnockoutSubscribable<T> extends KnockoutSubscribableFunctions<T> {
-	(): T;
-	(value: T): void;
-
 	subscribe(callback: (newValue: T) => void, target?: any, event?: string): KnockoutSubscription;
+	subscribe<TEvent>(callback: (newValue: TEvent) => void, target: any, event: string): KnockoutSubscription;
 	extend(requestedExtenders: { [key: string]: any; }): KnockoutSubscribable<T>;
 	getSubscriptionsCount(): number;
 }
@@ -70,6 +68,9 @@ interface KnockoutComputedStatic {
 }
 
 interface KnockoutComputed<T> extends KnockoutSubscribable<T>, KnockoutComputedFunctions<T> {
+	(): T;
+	(value: T): void;
+
 	peek(): T;
 	dispose(): void;
 	isActive(): boolean;
@@ -92,6 +93,9 @@ interface KnockoutObservableStatic {
 }
 
 interface KnockoutObservable<T> extends KnockoutSubscribable<T>, KnockoutObservableFunctions<T> {
+	(): T;
+	(value: T): void;
+
 	peek(): T;
 	valueHasMutated(): void;
 	valueWillMutate(): void;