diff --git a/types/raven/index.d.ts b/types/raven/index.d.ts
index e2d5e18198..eec1b00f2c 100644
--- a/types/raven/index.d.ts
+++ b/types/raven/index.d.ts
@@ -10,7 +10,7 @@ import { IncomingMessage, ServerResponse } from 'http';
 import { EventEmitter } from 'events';
 
 export const version: string;
-export function config(dsn: string | false, options?: ConstructorOptions): Client;
+export function config(dsn?: string | false, options?: ConstructorOptions): Client;
 export function wrap<T>(func: () => T): () => T;
 export function wrap<T>(options: any, func: () => T): () => T;
 export function interceptErr(ctx: any): Client;