diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 36a5a905..43f90a89 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -69,6 +69,7 @@ function Chain(options) {
   this.loaded = false;
   this.db = new bcoin.chaindb(this, options);
   this.total = 0;
+  this.adding = false;
   this.orphanLimit = options.orphanLimit || (20 << 20);
   this.pendingLimit = options.pendingLimit || (1024 << 20);
   this.locker = new bcoin.locker(this, this.add, this.pendingLimit);
@@ -1302,6 +1303,15 @@ Chain.prototype.onFlush = function onFlush(callback) {
   return this.locker.onFlush(callback);
 };
 
+/**
+ * Test whether the chain is in the process of adding blocks.
+ * @returns {Boolean}
+ */
+
+Chain.prototype.isBusy = function isBusy() {
+  return this.adding || this.locker.pending.length > 0;
+};
+
 /**
  * Add a block to the chain, perform all necessary verification.
  * @param {Block|MerkleBlock|CompactBlock} block
@@ -1321,6 +1331,8 @@ Chain.prototype.add = function add(block, callback, force) {
 
   callback = utils.wrap(callback, unlock);
 
+  this.adding = true;
+
   (function next(block, initial) {
     var hash = block.hash('hex');
     var prevHash = block.prevBlock;
@@ -1539,7 +1551,7 @@ Chain.prototype.add = function add(block, callback, force) {
         if (entry.chainwork.cmp(self.tip.chainwork) <= 0) {
           return self.db.save(entry, block, false, function(err) {
             if (err)
-              return callback(err);
+              return done(err);
 
             // Keep track of the number of blocks we
             // added and the number of orphans resolved.
@@ -1599,6 +1611,8 @@ Chain.prototype.add = function add(block, callback, force) {
         self.emit('full');
       }
 
+      self.adding = false;
+
       if (err)
         callback(err);
       else
diff --git a/lib/bcoin/pool.js b/lib/bcoin/pool.js
index 0179c592..3547110a 100644
--- a/lib/bcoin/pool.js
+++ b/lib/bcoin/pool.js
@@ -467,10 +467,11 @@ Pool.prototype._startInterval = function _startInterval() {
     if (self.chain.isFull())
       return;
 
-    if (self.chain.locker.pending.length > 0)
+    if (self.chain.isBusy())
       return self._startTimer();
 
     bcoin.debug('Stall recovery: loading again.');
+
     // self._load();
   }
 
@@ -1643,7 +1644,7 @@ Pool.prototype.scheduleRequests = function scheduleRequests(peer) {
 Pool.prototype._sendRequests = function _sendRequests(peer) {
   var size, items;
 
-  if (this.chain.locker.pending.length > 0)
+  if (this.chain.isBusy())
     return;
 
   if (peer.queue.block.length === 0)