//@filename: file.tsx //@jsx: preserve declare module JSX { interface Element { } interface ElementClass { render: any; } interface IntrinsicElements { } } interface Obj1type { new(n: string): { x: number }; } var Obj1: Obj1type; ; // Error, no render member interface Obj2type { (n: string): { x: number; render: any; }; } var Obj2: Obj2type; ; // OK