diff --git a/lib/Connection.js b/lib/Connection.js
index 4d0b36c..f2ebdcc 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -939,8 +939,10 @@ Connection.prototype._resTagged = function(info) {
     err.textCode = info.textCode;
     err.source = 'protocol';
   } else if (this._box) {
-    if (req.type === 'EXAMINE' || req.type === 'SELECT')
-      this._box.readOnly = (info.textCode.toUpperCase() === 'READ-ONLY');
+    if (req.type === 'EXAMINE' || req.type === 'SELECT') {
+      this._box.readOnly = (typeof info.textCode === 'string'
+                            && info.textCode.toUpperCase() === 'READ-ONLY');
+    }
 
     // According to RFC 3501, UID commands do not give errors for
     // non-existant user-supplied UIDs, so give the callback empty results
diff --git a/lib/Parser.js b/lib/Parser.js
index 216026d..86a535f 100644
--- a/lib/Parser.js
+++ b/lib/Parser.js
@@ -141,7 +141,7 @@ Parser.prototype._resTagged = function() {
     var m = RE_TAGGED.exec(this._buffer),
         tagnum = parseInt(m[1], 10),
         type = m[2].toLowerCase(),
-        textCode = (m[3] ? parseExpr(m[3], this._literals) : m[3]),
+        textCode = (m[3] ? parseTextCode(m[3], this._literals) : m[3]),
         text = m[4];
 
     this._literals = [];