diff --git a/lib/bcoin/keyring.js b/lib/bcoin/keyring.js
index f70bd8de..46417964 100644
--- a/lib/bcoin/keyring.js
+++ b/lib/bcoin/keyring.js
@@ -72,6 +72,9 @@ KeyRing.prototype.addKey = function addKey(key) {
   if (utils.indexOf(this.keys, key) !== -1)
     return;
 
+  if (this.keys.length === this.n)
+    throw new Error('Cannot add more keys.');
+
   utils.binaryInsert(this.keys, key, utils.cmp);
 };
 
@@ -81,6 +84,9 @@ KeyRing.prototype.addKey = function addKey(key) {
  */
 
 KeyRing.prototype.removeKey = function removeKey(key) {
+  if (this.keys.length === this.n)
+    throw new Error('Cannot remove key.');
+
   utils.binaryRemove(this.keys, key, utils.cmp);
 };
 
@@ -628,7 +634,7 @@ KeyRing.fromRaw = function fromRaw(data) {
 };
 
 /**
- * Test an object to see if it is an KeyRing.
+ * Test whether an object is a KeyRing.
  * @param {Object} obj
  * @returns {Boolean}
  */
diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index efdbba0f..47390902 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -560,7 +560,7 @@ TXDB.prototype._add = function add(tx, map, callback, force) {
           if (err)
             return callback(err);
 
-          self.walletdb.sync(tx, map, function(err) {
+          self.walletdb.syncOutputs(tx, map, function(err) {
             if (err)
               return callback(err);
 
@@ -751,7 +751,7 @@ TXDB.prototype._confirm = function _confirm(tx, map, callback, force) {
         if (err)
           return callback(err);
 
-        self.walletdb.sync(tx, map, function(err) {
+        self.walletdb.syncOutputs(tx, map, function(err) {
           if (err)
             return callback(err);
 
diff --git a/lib/bcoin/wallet.js b/lib/bcoin/wallet.js
index bd6a7f1d..55766a54 100644
--- a/lib/bcoin/wallet.js
+++ b/lib/bcoin/wallet.js
@@ -918,13 +918,8 @@ Wallet.prototype.scan = function scan(getByAddress, callback) {
       if (err)
         return callback(err);
 
-      if (result === 0) {
-        return self.save(function(err) {
-          if (err)
-            return callback(err);
-          return callback(null, total);
-        });
-      }
+      if (result === 0)
+        return callback(null, total);
 
       total += result;
 
@@ -1568,7 +1563,7 @@ function Account(options) {
   this.options = options;
   this.network = bcoin.network.get(options.network);
   this.db = options.db;
-  this.lookahead = options.lookahead != null ? options.lookahead : 5;
+  this.lookahead = Account.LOOKAHEAD;
 
   this.id = options.id;
   this.name = options.name;
@@ -1612,6 +1607,13 @@ function Account(options) {
 
 utils.inherits(Account, EventEmitter);
 
+/*
+ * Default address lookahead.
+ * @const {Number}
+ */
+
+Account.LOOKAHEAD = 5;
+
 /**
  * Open the account, register with the database.
  * @param {Function} callback
diff --git a/lib/bcoin/walletdb.js b/lib/bcoin/walletdb.js
index 65397adf..7e8ba4c4 100644
--- a/lib/bcoin/walletdb.js
+++ b/lib/bcoin/walletdb.js
@@ -143,36 +143,18 @@ WalletDB.prototype._init = function _init() {
   });
 
   this.tx.on('updated', function(tx, map) {
-    var balances = {};
-
     self.emit('updated', tx, map);
     map.all.forEach(function(path) {
       self.fire(path.id, 'updated', tx, path.name);
     });
-
-    utils.forEachSerial(map.output, function(path, next) {
-      if (self.listeners('balance').length === 0
-          && !self.hasListener(path.id, 'balance')) {
-        return next();
-      }
-
-      if (balances[path.id] != null)
-        return next();
-
-      self.getBalance(path.id, function(err, balance) {
-        if (err)
-          return next(err);
-
-        balances[path.id] = balance;
-
-        self.fire(path.id, 'balance', balance);
-
-        next();
-      });
-    }, function(err) {
+    self.updateBalances(tx, map, function(err, balances) {
       if (err)
         return self.emit('error', err);
 
+      Object.keys(balances).forEach(function(id) {
+        self.fire(id, 'balance', balances[id]);
+      });
+
       self.emit('balances', balances, map);
     });
   });
@@ -191,7 +173,36 @@ WalletDB.prototype._init = function _init() {
   });
 };
 
-WalletDB.prototype.sync = function sync(tx, map, callback) {
+WalletDB.prototype.updateBalances = function updateBalances(tx, map, callback) {
+  var self = this;
+  var balances = {};
+
+  utils.forEachSerial(map.output, function(path, next) {
+    if (self.listeners('balance').length === 0
+        && !self.hasListener(path.id, 'balance')) {
+      return next();
+    }
+
+    if (balances[path.id] != null)
+      return next();
+
+    self.getBalance(path.id, function(err, balance) {
+      if (err)
+        return next(err);
+
+      balances[path.id] = balance;
+
+      next();
+    });
+  }, function(err) {
+    if (err)
+      return callback(err);
+
+    return callback(null, balances);
+  });
+};
+
+WalletDB.prototype.syncOutputs = function syncOutputs(tx, map, callback) {
   var self = this;
   utils.forEachSerial(map.output, function(path, next) {
     self.syncOutputDepth(path.id, tx, next);
@@ -832,12 +843,12 @@ WalletDB.prototype.removeBlockSPV = function removeBlockSPV(block, callback) {
 
   callback = utils.ensure(callback);
 
-  this.tx.getHeightHashes(block.height, function(err, txs) {
+  this.tx.getHeightHashes(block.height, function(err, hashes) {
     if (err)
       return callback(err);
 
-    utils.forEachSerial(txs, function(tx, next) {
-      self.tx.unconfirm(tx, next);
+    utils.forEachSerial(hashes, function(hash, next) {
+      self.tx.unconfirm(hash, next);
     }, callback);
   });
 };
@@ -895,21 +906,9 @@ WalletDB.prototype.syncOutputDepth = function syncOutputDepth(id, tx, callback)
   });
 };
 
-WalletDB.prototype.createAddress = function createAddress(id, change, callback) {
+WalletDB.prototype.createAddress = function createAddress(id, name, change, callback) {
   this.fetchWallet(id, callback, function(wallet, callback) {
-    wallet.createAddress(change, callback);
-  });
-};
-
-WalletDB.prototype.getReceiveAddress = function getReceiveAddress(id, callback) {
-  this.fetchWallet(id, callback, function(wallet, callback) {
-    callback(null, wallet.receiveAddress);
-  });
-};
-
-WalletDB.prototype.getChangeAddress = function getChangeAddress(id, callback) {
-  this.fetchWallet(id, callback, function(wallet, callback) {
-    callback(null, wallet.changeAddress);
+    wallet.createAddress(name, change, callback);
   });
 };
 
@@ -947,15 +946,15 @@ WalletDB.prototype.createTX = function createTX(id, options, outputs, callback)
   });
 };
 
-WalletDB.prototype.addKey = function addKey(id, key, callback) {
+WalletDB.prototype.addKey = function addKey(id, name, key, callback) {
   this.fetchWallet(id, callback, function(wallet, callback) {
-    wallet.addKey(key, callback);
+    wallet.addKey(name, key, callback);
   });
 };
 
-WalletDB.prototype.removeKey = function removeKey(id, key, callback) {
+WalletDB.prototype.removeKey = function removeKey(id, name, key, callback) {
   this.fetchWallet(id, callback, function(wallet, callback) {
-    wallet.removeKey(key, callback);
+    wallet.removeKey(name, key, callback);
   });
 };
 
@@ -1013,7 +1012,8 @@ function serializePaths(out) {
 }
 
 function isAlpha(key) {
-  return /^[a-zA-Z0-9]+$/.test(key);
+  // We allow /-~ (exclusive), 0-} (inclusive)
+  return /^[\u0030-\u007d]+$/.test(key);
 }
 
 /*
diff --git a/package.json b/package.json
index a4e0e955..60172024 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
   },
   "homepage": "https://github.com/indutny/bcoin",
   "engines": {
-    "node": ">= 0.8.0"
+    "node": ">= 0.10.0"
   },
   "dependencies": {
     "bn.js": "4.11.0",