diff --git a/types/websocket/index.d.ts b/types/websocket/index.d.ts
index f67a5da142..0087c7a3d1 100644
--- a/types/websocket/index.d.ts
+++ b/types/websocket/index.d.ts
@@ -62,8 +62,8 @@ export interface IConfig {
 }
 
 export interface IServerConfig extends IConfig {
-    /** The http server instance to attach to */
-    httpServer: http.Server;
+    /** The http or https server instance(s) to attach to */
+    httpServer: http.Server | https.Server | (http.Server | https.Server)[];
 
     /**
      * The maximum allowed received frame size in bytes.