diff --git a/lib/pack.js b/lib/pack.js
index 67214944..42433f7e 100644
--- a/lib/pack.js
+++ b/lib/pack.js
@@ -48,8 +48,9 @@ const ONDRAIN = Symbol('ondrain')
 
 const fs = require('fs')
 const path = require('path')
+const warner = require('./warn-mixin.js')
 
-class Pack extends MiniPass {
+const Pack = warner(class Pack extends MiniPass {
   constructor (opt) {
     super(opt)
     opt = opt || Object.create(null)
@@ -240,10 +241,6 @@ class Pack extends MiniPass {
       this[PIPE](job)
   }
 
-  warn (msg, data) {
-    return this.emit('warn', msg, data)
-  }
-
   [ENTRY] (job) {
     this[JOBS] += 1
     try {
@@ -303,7 +300,7 @@ class Pack extends MiniPass {
       this.zip.pause()
     return super.pause()
   }
-}
+})
 
 class PackSync extends Pack {
   constructor (opt) {