diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 2c6bface..ac7726b4 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -1500,8 +1500,6 @@ Chain.prototype.add = function add(block, callback, force) {
           }
         }
 
-        assert(prev);
-
         // Explanation: we try to keep as much data
         // off the javascript heap as possible. Blocks
         // in the future may be 8mb or 20mb, who knows.
@@ -1882,15 +1880,15 @@ Chain.prototype.getHashRange = function getHashRange(start, end, callback) {
       if (!start || !end)
         return callback(null, hashes);
 
-      utils.forRange(start.height, end.height + 1, function(i, next) {
-        self.db.get(i, function(err, entry) {
+      utils.forRangeSerial(start.height, end.height + 1, function(i, next) {
+        self.db.getHash(i, function(err, hash) {
           if (err)
             return next(err);
 
-          if (!entry)
+          if (!hash)
             return next(new Error('No entry for hash range.'));
 
-          hashes[i - start.height] = entry.hash;
+          hashes.push(hash);
 
           next();
         });
@@ -1923,24 +1921,6 @@ Chain.prototype.getLocator = function getLocator(start, callback, force) {
 
   callback = utils.wrap(callback, unlock);
 
-  function getAncestor(entry, height, main, callback) {
-    if (height === 0)
-      return callback(null, { hash: network.genesis.hash, height: 0 });
-
-    if (!main)
-      return entry.getAncestorByHeight(height, callback);
-
-    return self.db.getHash(height, function(err, hash) {
-      if (err)
-        return callback(err);
-
-      if (!hash)
-        return callback();
-
-      return callback(null, { hash: hash, height: height });
-    });
-  }
-
   if (start == null)
     start = this.tip.hash;
 
@@ -1980,7 +1960,21 @@ Chain.prototype.getLocator = function getLocator(start, callback, force) {
         if (hashes.length > 10)
           step *= 2;
 
-        getAncestor(entry, height, main, next);
+        if (height === 0)
+          return next(null, { hash: network.genesis.hash, height: 0 });
+
+        if (!main)
+          return entry.getAncestorByHeight(height, next);
+
+        self.db.getHash(height, function(err, hash) {
+          if (err)
+            return next(err);
+
+          if (!hash)
+            return next();
+
+          next(null, { hash: hash, height: height });
+        });
       })(null, entry);
     });
   });