diff --git a/lib/Connection.js b/lib/Connection.js
index 1dae2c7..356e085 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -593,7 +593,7 @@ Connection.prototype._store = function(which, uids, cfg, cb) {
   uids = uids.join(',');
 
   var modifiers = '';
-  if (cfg.modseq !== undefined)
+  if (cfg.modseq !== undefined && !this._box.nomodseq)
     modifiers += 'UNCHANGEDSINCE ' + cfg.modseq + ' ';
 
   this._enqueue(which + 'STORE ' + uids + ' '
@@ -742,7 +742,7 @@ Connection.prototype._fetch = function(which, uids, options) {
     fetching.push('X-GM-MSGID');
     fetching.push('X-GM-LABELS');
   }
-  if (this.serverSupports('CONDSTORE'))
+  if (this.serverSupports('CONDSTORE') && !this._box.nomodseq)
     fetching.push('MODSEQ');
 
   fetching.push('UID');
@@ -779,7 +779,8 @@ Connection.prototype._fetch = function(which, uids, options) {
       modstr = ' (';
   for (i = 0, len = modkeys.length, key; i < len; ++i) {
     key = modkeys[i].toUpperCase();
-    if (key === 'CHANGEDSINCE' && this.serverSupports('CONDSTORE'))
+    if (key === 'CHANGEDSINCE' && this.serverSupports('CONDSTORE')
+        && !this._box.nomodseq)
       modstr += key + ' ' + modifiers[modkeys[i]] + ' ';
   }
   if (modstr.length > 2) {
@@ -1260,6 +1261,8 @@ Connection.prototype._resUntagged = function(info) {
           permFlags.splice(permFlags.indexOf(keywords[i]), 1);
       } else if (key === 'UIDNOTSTICKY')
         this._box.persistentUIDs = false;
+      else if (key === 'NOMODSEQ')
+        this._box.nomodseq = true;
     } else if (typeof info.textCode === 'string'
                && info.textCode.toUpperCase() === 'UIDVALIDITY')
       this.emit('uidvalidity', info.text);
@@ -1477,6 +1480,7 @@ Connection.prototype._createCurrentBox = function() {
     keywords: [],
     newKeywords: false,
     persistentUIDs: true,
+    nomodseq: false,
     messages: {
       total: 0,
       new: 0