diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 64d49182..f2e70544 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -1103,7 +1103,7 @@ Chain.prototype.disconnect = function disconnect(entry, callback) {
  * Connect an entry to the chain (updates the tip).
  * This will do contextual-verification on the block
  * (necessary because we cannot validate the inputs
- * in side chains when they come in).
+ * in alternate chains when they come in).
  * @param {ChainBlock} entry
  * @param {Function} callback
  */
@@ -1159,7 +1159,7 @@ Chain.prototype.connect = function connect(entry, callback) {
 /**
  * Set the best chain. This is called on every valid block
  * that comes in. It may add and connect the block (main chain),
- * save the block without connection (side chain), or
+ * save the block without connection (alternate chain), or
  * reorganize the chain (a higher fork).
  * @private
  * @param {ChainBlock} entry
@@ -1531,7 +1531,7 @@ Chain.prototype.add = function add(block, callback, force) {
           height: height
         }, prev);
 
-        // The block is on a side chain if the
+        // The block is on a alternate chain if the
         // chainwork is less than or equal to
         // our tip's. Add the block but do _not_
         // connect the inputs.
diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index 0d3cd6d9..678a52f9 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -57,17 +57,17 @@ function ChainDB(chain, options) {
 
   this.loaded = false;
 
-  // Need to cache up to the retarget interval
-  // if we're going to be checking the damn
-  // target all the time.
-  if (network.pow.allowMinDifficultyBlocks)
-    this._cacheWindow = network.pow.retargetInterval + 1;
-  else
-    this._cacheWindow = network.block.majorityWindow + 1;
+  // We want at least 1 retarget interval cached
+  // for retargetting, but we need at least two
+  // cached for optimal versionbits state checks.
+  // We add a padding of 100 for forked chains,
+  // reorgs, chain locator creation and the bip34
+  // check.
+  this.cacheWindow = (network.pow.retargetInterval + 1) * 2 + 100;
 
   this.coinCache = new NullCache(100000);
-  this.cacheHash = new bcoin.lru(this._cacheWindow);
-  this.cacheHeight = new bcoin.lru(this._cacheWindow);
+  this.cacheHash = new bcoin.lru(this.cacheWindow);
+  this.cacheHeight = new bcoin.lru(this.cacheWindow);
 
   this._init();
 }
@@ -689,7 +689,7 @@ ChainDB.prototype.reset = function reset(block, callback) {
 
 /**
  * Test whether the chain contains a block in the
- * main chain or side chain. Side chains will only
+ * main chain or an alternate chain. Alternate chains will only
  * be tested if the lookup is done by hash.
  * @param {Hash|Number} height - Hash or height.
  * @param {Function} callback - Returns [Error, Boolean].