diff --git a/lib/wallet/masterkey.js b/lib/wallet/masterkey.js
index 94489d04..e9a13d74 100644
--- a/lib/wallet/masterkey.js
+++ b/lib/wallet/masterkey.js
@@ -279,7 +279,7 @@ MasterKey.prototype.decipher = function decipher(data, iv) {
  * the timer if there is one.
  */
 
-MasterKey.prototype.destroy = function destroy() {
+MasterKey.prototype.lock = function lock() {
   if (!this.encrypted) {
     assert(this.timer == null);
     assert(this.key);
@@ -299,6 +299,15 @@ MasterKey.prototype.destroy = function destroy() {
   }
 };
 
+/**
+ * Destroy the key permanently.
+ */
+
+MasterKey.prototype.destroy = function destroy() {
+  this.lock();
+  this.locker.destroy();
+};
+
 /**
  * Decrypt the key permanently.
  * @param {Buffer|String} passphrase - Zero this yourself.
@@ -332,7 +341,7 @@ MasterKey.prototype._decrypt = co(function* decrypt(passphrase) {
   if (!passphrase)
     return;
 
-  this.destroy();
+  this.lock();
 
   key = yield this.derive(passphrase);
   data = crypto.decipher(this.ciphertext, key, this.iv);
diff --git a/lib/wallet/wallet.js b/lib/wallet/wallet.js
index 06414595..148ee504 100644
--- a/lib/wallet/wallet.js
+++ b/lib/wallet/wallet.js
@@ -81,7 +81,7 @@ function Wallet(db, options) {
   this.accountDepth = 0;
   this.token = constants.ZERO_HASH;
   this.tokenDepth = 0;
-  this.master = null;
+  this.master = new MasterKey();
 
   this.txdb = new TXDB(this);
   this.account = null;
@@ -99,27 +99,27 @@ utils.inherits(Wallet, EventEmitter);
  */
 
 Wallet.prototype.fromOptions = function fromOptions(options) {
-  var master = options.master;
+  var key = options.master;
   var id, token;
 
-  if (!MasterKey.isMasterKey(master)) {
-    if (!master)
-      master = HD.fromMnemonic(null, this.network);
+  if (MasterKey.isMasterKey(key)) {
+    this.master.fromOptions(key);
+  } else {
+    if (!key)
+      key = HD.fromMnemonic(null, this.network);
 
-    if (HD.isExtended(master))
-      master = HD.fromBase58(master);
+    if (HD.isExtended(key))
+      key = HD.fromBase58(key);
 
-    assert(HD.isPrivate(master),
+    assert(HD.isPrivate(key),
       'Must create wallet with hd private key.');
 
-    assert(master.network === this.network,
+    assert(key.network === this.network,
       'Network mismatch for master key.');
 
-    master = MasterKey.fromKey(master);
+    this.master.fromKey(key);
   }
 
-  this.master = master;
-
   if (options.wid != null) {
     assert(utils.isNumber(options.wid));
     this.wid = options.wid;
@@ -589,7 +589,7 @@ Wallet.prototype.lock = co(function* lock() {
   var unlock1 = yield this.writeLock.lock();
   var unlock2 = yield this.fundLock.lock();
   try {
-    this.master.destroy();
+    this.master.lock();
   } finally {
     unlock2();
     unlock1();