diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index 9cf09789..c5148bde 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -311,23 +311,16 @@ utils.pbkdf2 = function pbkdf2(key, salt, iterations, dkLen) {
   var DK, U, T, block1, l, r;
   var i, j, k, destPos, len;
 
+  if (typeof key === 'string')
+    key = new Buffer(key, 'utf8');
+
+  if (typeof salt === 'string')
+    salt = new Buffer(salt, 'utf8');
+
   if (crypto && crypto.pbkdf2Sync)
     return crypto.pbkdf2Sync(key, salt, iterations, dkLen, 'sha512');
 
-  if (dkLen > (Math.pow(2, 32) - 1) * hLen)
-    throw Error('Requested key length too long');
-
-  if (typeof key !== 'string' && typeof key.length !== 'number')
-    throw new TypeError('key must a string or array');
-
-  if (typeof salt !== 'string' && typeof salt.length !== 'number')
-    throw new TypeError('salt must a string or array');
-
-  if (typeof key === 'string')
-    key = new Buffer(key);
-
-  if (typeof salt === 'string')
-    salt = new Buffer(salt);
+  assert(dkLen <= 0xffffffff * hLen, 'Requested key length too long');
 
   DK = new Buffer(dkLen);
   U = new Buffer(hLen);
diff --git a/test/mnemonic-test.js b/test/mnemonic-test.js
index 18e13de7..fc52884e 100644
--- a/test/mnemonic-test.js
+++ b/test/mnemonic-test.js
@@ -13,9 +13,9 @@ describe('Mnemonic', function() {
     var xpriv = data[3];
     it('should create an english mnemonic (' + i + ')', function() {
       var mnemonic = new bcoin.hd.mnemonic({
-        passphrase: 'TREZOR',
         lang: 'english',
-        entropy: entropy
+        entropy: entropy,
+        passphrase: 'TREZOR'
       });
       mnemonic.toSeed();
       assert.equal(mnemonic.phrase, phrase);
@@ -24,7 +24,6 @@ describe('Mnemonic', function() {
       assert.equal(key.xprivkey, xpriv);
     });
   });
-  return;
   mnemonic2.forEach(function(data, i) {
     var entropy = new Buffer(data.entropy, 'hex');
     var phrase = data.mnemonic;