diff --git a/lib/attribute.js b/lib/attribute.js
index 5d9a453..d1ba081 100644
--- a/lib/attribute.js
+++ b/lib/attribute.js
@@ -2,6 +2,8 @@
 
 var assert = require('assert');
 
+var asn1 = require('asn1');
+
 var Protocol = require('./protocol');
 
 
@@ -14,32 +16,69 @@ function Attribute(options) {
       throw new TypeError('options must be an object');
     if (options.type && typeof(options.type) !== 'string')
       throw new TypeError('options.type must be a string');
-    if (options.vals && !Array.isArray(options.vals))
-      throw new TypeErrr('options.vals must be an array[string]');
-    if (options.vals && options.vals.length) {
-      options.vals.forEach(function(v) {
-        if (typeof(v) !== 'string')
-          throw new TypeErrr('options.vals must be an array[string]');
-      });
-    }
   } else {
     options = {};
   }
 
-  this.type = options.type || '';
-  this.vals = options.vals ? options.vals.slice(0) : [];
-
   var self = this;
+
+  this.type = options.type || '';
+  this._vals = [];
+
+  this.__defineGetter__('vals', function() {
+    var _vals = [];
+
+    self._vals.forEach(function(v) {
+      if (/;binary$/.test(self.type)) {
+        _vals.push(v.toString('base64'));
+      } else {
+        _vals.push(v.toString('utf8'));
+      }
+    });
+
+    return _vals;
+  });
+
+  this.__defineSetter__('vals', function(vals) {
+    if (Array.isArray(vals)) {
+      vals.forEach(function(v) {
+        self.addValue(v);
+      });
+    } else {
+      self.addValue(vals);
+    }
+  });
+
+  this.__defineGetter__('buffers', function() {
+    return self._vals;
+  });
+
   this.__defineGetter__('json', function() {
     return {
       type: self.type,
       vals: self.vals
     };
   });
+
+  if (options.vals)
+    this.vals = options.vals;
+
 }
 module.exports = Attribute;
 
 
+Attribute.prototype.addValue = function(val) {
+  if (Buffer.isBuffer(val)) {
+    this._vals.push(val);
+  } else {
+    var encoding = 'utf8';
+    if (/;binary$/.test(this.type))
+      encoding = 'base64';
+    this._vals.push(new Buffer(val + '', encoding));
+  }
+};
+
+
 Attribute.compare = function(a, b) {
   if (!(a instanceof Attribute) || !(b instanceof Attribute))
     throw new TypeError('can only compare Attributes');
@@ -57,13 +96,6 @@ Attribute.compare = function(a, b) {
   return 0;
 };
 
-Attribute.prototype.addValue = function(val) {
-  if (typeof(val) !== 'string')
-    throw new TypeError('val (string) required');
-
-  this.vals.push(val);
-};
-
 
 Attribute.prototype.parse = function(ber) {
   assert.ok(ber);
@@ -75,7 +107,7 @@ Attribute.prototype.parse = function(ber) {
     if (ber.readSequence(Protocol.LBER_SET)) {
       var end = ber.offset + ber.length;
       while (ber.offset < end)
-        this.vals.push(ber.readString());
+        this._vals.push(ber.readString(asn1.Ber.OctetString, true));
     }
   }
 
@@ -86,10 +118,15 @@ Attribute.prototype.parse = function(ber) {
 Attribute.prototype.toBer = function(ber) {
   assert.ok(ber);
 
+  var vals = [];
+  this._vals.forEach(function(v) {
+    vals.push(v.toString('utf8'));
+  });
+
   ber.startSequence();
   ber.writeString(this.type);
   ber.startSequence(Protocol.LBER_SET);
-  ber.writeStringArray(this.vals && this.vals.length ? this.vals : []);
+  ber.writeStringArray(vals);
   ber.endSequence();
   ber.endSequence();
 
@@ -108,7 +145,8 @@ Attribute.isAttribute = function(attr) {
   if (!attr.type || typeof(attr.type) !== 'string') return false;
   if (!attr.vals || !Array.isArray(attr.vals)) return false;
   for (var i = 0; i < attr.vals.length; i++)
-    if (typeof(attr.vals[i]) !== 'string') return false;
+    if (typeof(attr.vals[i]) !== 'string' && !Buffer.isBuffer(attr.vals[i]))
+      return false;
 
   return true;
 };
diff --git a/lib/messages/search_entry.js b/lib/messages/search_entry.js
index 3934767..96f7dce 100644
--- a/lib/messages/search_entry.js
+++ b/lib/messages/search_entry.js
@@ -87,20 +87,7 @@ SearchEntry.prototype.fromObject = function(obj) {
   this.attributes = [];
 
   Object.keys(obj).forEach(function(k) {
-    var attr = new Attribute({type: k, vals: []});
-
-    if (Array.isArray(obj[k])) {
-      obj[k].forEach(function(v) {
-        if (typeof(v) !== 'string')
-          v = '' + v;
-
-        attr.vals.push(v);
-      });
-    } else {
-      attr.vals.push(obj[k] + '');
-    }
-
-    self.attributes.push(attr);
+    self.attributes.push(new Attribute({type: k, vals: obj[k]}));
   });
 
   return true;
diff --git a/package.json b/package.json
index 44723f8..0ad2e95 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "node": ">=0.4"
   },
   "dependencies": {
-    "asn1": "~0.1.5",
+    "asn1": "~0.1.6",
     "buffertools": "~1.0.3",
     "dtrace-provider": "~0.0.3",
     "sprintf": "~0.1.1"
diff --git a/tst/client.test.js b/tst/client.test.js
index 6d744d8..a208dc6 100644
--- a/tst/client.test.js
+++ b/tst/client.test.js
@@ -83,7 +83,8 @@ test('setup', function(t) {
       res.send(res.createSearchEntry({
         objectName: req.dn,
         attributes: {
-          'foo;binary': '\u00bd + \u00bc = \u00be'
+          'foo;binary': 'wr0gKyDCvCA9IMK+',
+          'objectclass': 'binary'
         }
       }));
     } else {
@@ -431,6 +432,39 @@ test('search empty attribute', function(t) {
 });
 
 
+test('GH-21 binary attributes', function(t) {
+  client.search('cn=bin, ' + SUFFIX, '(objectclass=*)', function(err, res) {
+    t.ifError(err);
+    t.ok(res);
+    var gotEntry = 0;
+    var expect = new Buffer('\u00bd + \u00bc = \u00be', 'utf8');
+    res.on('searchEntry', function(entry) {
+      t.ok(entry);
+      t.ok(entry instanceof ldap.SearchEntry);
+      t.equal(entry.dn.toString(), 'cn=bin, ' + SUFFIX);
+      t.ok(entry.attributes);
+      t.ok(entry.attributes.length);
+      t.equal(entry.attributes[0].type, 'foo;binary');
+      t.equal(entry.attributes[0].vals[0], expect.toString('base64'));
+      t.equal(entry.attributes[0].buffers[0].toString('base64'),
+              expect.toString('base64'));
+      t.ok(entry.object);
+      gotEntry++;
+    });
+    res.on('error', function(err) {
+      t.fail(err);
+    });
+    res.on('end', function(res) {
+      t.ok(res);
+      t.ok(res instanceof ldap.SearchResponse);
+      t.equal(res.status, 0);
+      t.equal(gotEntry, 1);
+      t.end();
+    });
+  });
+});
+
+
 test('GH-23 case insensitive attribute filtering', function(t) {
   var opts = {
     filter: '(objectclass=*)',