diff --git a/restify/restify.d.ts b/restify/restify.d.ts
index 826b2ca430..1464176eb3 100644
--- a/restify/restify.d.ts
+++ b/restify/restify.d.ts
@@ -251,6 +251,7 @@ declare module "restify" {
 
   interface Next {
     (err?: any): any;
+    ifError: (err?: any) => any;
   }
 
   interface RequestHandler {