diff --git a/imap.js b/imap.js
index f7fc743..65ec144 100644
--- a/imap.js
+++ b/imap.js
@@ -404,7 +404,7 @@ ImapConnection.prototype.openBox = function(name, readOnly, cb) {
     this._resetBox();
   if (typeof cb === 'undefined') {
     if(typeof readOnly === 'undefined') {
-      cb = function(){};
+      cb = emptyFn;
     } else {
       cb = readOnly;
     }
@@ -1418,4 +1418,4 @@ function pipe(pair, socket) {
   socket.on('close', onclose);
 
   return cleartext;
-}
\ No newline at end of file
+}