diff --git a/lib/imap.js b/lib/imap.js
index 1f50b96..ed7fb67 100644
--- a/lib/imap.js
+++ b/lib/imap.js
@@ -335,7 +335,7 @@ ImapConnection.prototype.connect = function(loginCb) {
             if (details['x-gm-labels'] !== undefined) {
               var labels = details['x-gm-labels'];
               for (var i=0, len=labels.length; i<len; ++i)
-                labels[i] = labels[i].replace(RE_ESCAPE, '\\');
+                labels[i] = ('' + labels[i]).replace(RE_ESCAPE, '\\')
             }
 
             if (isUnsolicited)