diff --git a/pg/pg.d.ts b/pg/pg.d.ts
index 88b3debe4..64a92d96b 100644
--- a/pg/pg.d.ts
+++ b/pg/pg.d.ts
@@ -9,8 +9,8 @@ declare module "pg" {
     import events = require("events");
     import stream = require("stream");
 
-    export function connect(connection: string, callback: (err: Error, client: Client, done: () => void) => void): void;
-    export function connect(config: ClientConfig, callback: (err: Error, client: Client, done: () => void) => void): void;
+    export function connect(connection: string, callback: (err: Error, client: Client, done: (err?: any) => void) => void): void;
+    export function connect(config: ClientConfig, callback: (err: Error, client: Client, done: (err?: any) => void) => void): void;
     export function end(): void;
 
     export interface ConnectionConfig {