diff --git a/react/react-tests.ts b/react/react-tests.ts
index f0267d907..25185867e 100644
--- a/react/react-tests.ts
+++ b/react/react-tests.ts
@@ -104,4 +104,4 @@ var Timer = React.createClass({displayName: 'Timer',
     }
 });
 
-React.render(Timer(null), mountNode);
\ No newline at end of file
+React.render(Timer(), mountNode);
\ No newline at end of file
diff --git a/react/react.d.ts b/react/react.d.ts
index 40522920f..32249bd34 100644
--- a/react/react.d.ts
+++ b/react/react.d.ts
@@ -4,7 +4,7 @@
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
 
 declare module "react" {
-export = React;
+    export = React;
 }
 
 declare module React {
@@ -50,11 +50,11 @@ declare module React {
 
 
     export interface ReactComponentFactory<P> {
-        (properties: P, ...children: any[]): ReactComponentElement<P>;
+        (properties?: P, ...children: any[]): ReactComponentElement<P>;
     }
 
     export interface ReactElementFactory<P> {
-        (properties: P, ...children: any[]): ReactDOMElement<P>;
+        (properties?: P, ...children: any[]): ReactDOMElement<P>;
     }
 
     export interface DomElement extends ReactElementFactory<DomAttributes> {