diff --git a/lib/wallet/account.js b/lib/wallet/account.js
index 9d74ab5b..d6d91790 100644
--- a/lib/wallet/account.js
+++ b/lib/wallet/account.js
@@ -67,7 +67,7 @@ function Account(db, options) {
   this.receiveDepth = 0;
   this.changeDepth = 0;
   this.nestedDepth = 0;
-  this.lookahead = 10;
+  this.lookahead = 20;
   this.accountKey = null;
   this.keys = [];
 
@@ -218,7 +218,7 @@ Account.fromOptions = function fromOptions(db, options) {
  * @const {Number}
  */
 
-Account.MAX_LOOKAHEAD = 20;
+Account.MAX_LOOKAHEAD = 50;
 
 /**
  * Attempt to intialize the account (generating
@@ -719,6 +719,52 @@ Account.prototype.syncDepth = co(function* syncDepth(receive, change, nested) {
   return result;
 });
 
+/**
+ * Allocate new lookahead addresses.
+ * @param {Number} lookahead
+ * @returns {Promise}
+ */
+
+Account.prototype.setLookahead = co(function* setLookahead(lookahead) {
+  var i, key, depth, target;
+
+  if (lookahead <= this.lookahead) {
+    this.db.logger.warning(
+      'Lookahead is not increasing for: %s/%s.',
+      this.id, this.name);
+    return;
+  }
+
+  depth = this.receiveDepth + this.lookahead
+  target = this.receiveDepth + lookahead;
+
+  for (i = depth; i < target; i++) {
+    key = this.deriveReceive(i);
+    yield this.saveKey(key);
+  }
+
+  depth = this.changeDepth + this.lookahead
+  target = this.changeDepth + lookahead;
+
+  for (i = depth; i < target; i++) {
+    key = this.deriveChange(i);
+    yield this.saveKey(key);
+  }
+
+  if (this.witness) {
+    depth = this.nestedDepth + this.lookahead
+    target = this.nestedDepth + lookahead;
+
+    for (i = depth; i < target; i++) {
+      key = this.deriveNested(i);
+      yield this.saveKey(key);
+    }
+  }
+
+  this.lookahead = lookahead;
+  this.save();
+});
+
 /**
  * Convert the account to a more inspection-friendly object.
  * @returns {Object}
diff --git a/lib/wallet/wallet.js b/lib/wallet/wallet.js
index b01c3388..6439dddc 100644
--- a/lib/wallet/wallet.js
+++ b/lib/wallet/wallet.js
@@ -1794,6 +1794,58 @@ Wallet.prototype.getOutputPaths = co(function* getOutputPaths(tx) {
   return paths;
 });
 
+/**
+ * Increase lookahead for account.
+ * @param {(Number|String)?} account
+ * @param {Number} lookahead
+ * @returns {Promise}
+ */
+
+Wallet.prototype.setLookahead = co(function* setLookahead(acct, lookahead) {
+  var unlock = yield this.writeLock.lock();
+  try {
+    return this._setLookahead(acct, lookahead);
+  } finally {
+    unlock();
+  }
+});
+
+/**
+ * Increase lookahead for account (without a lock).
+ * @private
+ * @param {(Number|String)?} account
+ * @param {Number} lookahead
+ * @returns {Promise}
+ */
+
+Wallet.prototype._setLookahead = co(function* setLookahead(acct, lookahead) {
+  var account;
+
+  if (lookahead == null) {
+    lookahead = acct;
+    acct = null;
+  }
+
+  if (acct == null)
+    acct = 0;
+
+  account = yield this.getAccount(acct);
+
+  if (!account)
+    throw new Error('Account not found.');
+
+  this.start();
+
+  try {
+    yield account.setLookahead(lookahead);
+  } catch (e) {
+    this.drop();
+    throw e;
+  }
+
+  yield this.commit();
+});
+
 /**
  * Sync address depths based on a transaction's outputs.
  * This is used for deriving new addresses when
diff --git a/lib/wallet/walletdb.js b/lib/wallet/walletdb.js
index 5bdc35b3..dc90434b 100644
--- a/lib/wallet/walletdb.js
+++ b/lib/wallet/walletdb.js
@@ -190,6 +190,7 @@ function WalletDB(options) {
   this.depth = 0;
   this.wallets = {};
   this.keepBlocks = this.network.block.keepBlocks;
+  this.rescanning = false;
 
   // We need one read lock for `get` and `create`.
   // It will hold locks specific to wallet ids.
@@ -387,6 +388,7 @@ WalletDB.prototype._rescan = co(function* rescan(height) {
 
 WalletDB.prototype.scan = co(function* scan(height) {
   var self = this;
+  var iter = this._addBlock.bind(this);
   var tip;
 
   if (!this.client)
@@ -405,9 +407,13 @@ WalletDB.prototype.scan = co(function* scan(height) {
 
   tip = yield this.getTip();
 
-  yield this.client.scan(tip.hash, this.filter, function(block, txs) {
-    return self._addBlock(block, txs);
-  });
+  this.rescanning = true;
+
+  try {
+    yield this.client.scan(tip.hash, this.filter, iter);
+  } finally {
+    this.rescanning = false;
+  }
 });
 
 /**
diff --git a/migrate/walletdb5to6.js b/migrate/walletdb5to6.js
index cb36f202..5737cc05 100644
--- a/migrate/walletdb5to6.js
+++ b/migrate/walletdb5to6.js
@@ -228,6 +228,42 @@ function r(wid, index, hash) {
   return key;
 }
 
+var updateLookahead = co(function* updateLookahead() {
+  var WalletDB = require('../lib/wallet/walletdb');
+  var i, j, db, wallet;
+
+  db = new WalletDB({
+    network: process.argv[3],
+    db: 'leveldb',
+    location: file,
+    witness: false,
+    useCheckpoints: false,
+    maxFiles: 64,
+    resolution: false,
+    verify: false
+  });
+
+  yield db.open();
+
+  for (i = 1; i < db.depth; i++) {
+    wallet = yield db.get(i);
+    assert(wallet);
+    console.log('Updating wallet lookahead: %s', wallet.id);
+    for (j = 0; j < wallet.accountDepth; j++)
+      yield wallet.setLookahead(j, 20);
+  }
+
+  yield db.close();
+});
+
+var unstate = co(function* unstate() {
+  yield db.open();
+  batch = db.batch();
+  yield wipeTXDB();
+  yield batch.write();
+  yield db.close();
+});
+
 co.spawn(function* () {
   yield db.open();
   batch = db.batch();
@@ -239,6 +275,8 @@ co.spawn(function* () {
   yield patchPathMaps();
   yield batch.write();
   yield db.close();
+  yield updateLookahead();
+  yield unstate();
 }).then(function() {
   console.log('Migration complete.');
   console.log('Rescan is required...');