diff --git a/ws/index.d.ts b/ws/index.d.ts
index 733f11f608..172372d286 100644
--- a/ws/index.d.ts
+++ b/ws/index.d.ts
@@ -107,14 +107,6 @@ declare namespace WebSocket {
         memLevel?: number;
     }
 
-    export interface IPerMessageDeflateOptions {
-        serverNoContextTakeover?: boolean;
-        clientNoContextTakeover?: boolean;
-        serverMaxWindowBits?: number;
-        clientMaxWindowBits?: number;
-        memLevel?: number;
-    }
-
     export interface IServerOptions {
         host?: string;
         port?: number;