diff --git a/types/ws/index.d.ts b/types/ws/index.d.ts
index 1231d5af97..b99f9e4d88 100644
--- a/types/ws/index.d.ts
+++ b/types/ws/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for ws 5.1
+// Type definitions for ws 6.0
 // Project: https://github.com/websockets/ws
 // Definitions by: Paul Loyd <https://github.com/loyd>
 //                 Matt Silverlock <https://github.com/elithrar>
@@ -120,7 +120,7 @@ declare namespace WebSocket {
      * whether or not to accept the handshake.
      */
     type VerifyClientCallbackAsync = (info: { origin: string; secure: boolean; req: http.IncomingMessage }
-        , callback: (res: boolean, code?: number, message?: string) => void) => void;
+        , callback: (res: boolean, code?: number, message?: string, headers?: http.OutgoingHttpHeaders) => void) => void;
 
     interface ClientOptions {
         protocol?: string;
@@ -149,8 +149,17 @@ declare namespace WebSocket {
         clientNoContextTakeover?: boolean;
         serverMaxWindowBits?: number;
         clientMaxWindowBits?: number;
-        level?: number;
-        memLevel?: number;
+        zlibDeflateOptions?: {
+            flush?: number;
+            finishFlush?: number;
+            chunkSize?: number;
+            windowBits?: number;
+            level?: number;
+            memLevel?: number;
+            strategy?: number;
+            dictionary?: Buffer | Buffer[] | DataView;
+            info?: boolean;
+        };
         threshold?: number;
         concurrencyLimit?: number;
     }
diff --git a/types/ws/ws-tests.ts b/types/ws/ws-tests.ts
index 1b30da48ed..bc62d9de98 100644
--- a/types/ws/ws-tests.ts
+++ b/types/ws/ws-tests.ts
@@ -88,7 +88,20 @@ import * as https from 'https';
             clientNoContextTakeover: true,
             serverMaxWindowBits: 0,
             clientMaxWindowBits: 0,
-            memLevel: 0
+            zlibDeflateOptions: {
+                flush: 0,
+                finishFlush: 0,
+                chunkSize: 0,
+                windowBits: 0,
+                level: 0,
+                memLevel: 0,
+                strategy: 0,
+                dictionary: new Buffer('test'),
+                info: false
+            }
+        },
+        verifyClient: (info: any, cb: any) => {
+            cb(true, 123, 'message', { Upgrade: "websocket" });
         }
     });
 }