diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 38bcd569..4970f21f 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -735,6 +735,9 @@ ChainDB.prototype._init = function _init() {
   }
 
   this.size = this.getSize();
+
+  assert(this.size % BLOCK_SIZE === 0);
+
   this.fd = fs.openSync(this.file, 'r+');
 };
 
@@ -764,7 +767,7 @@ ChainDB.prototype.getSize = function getSize() {
 
 ChainDB.prototype.count = function count() {
   var len = this.size / BLOCK_SIZE;
-  assert(len === (len | 0));
+  assert(len % 1 === 0);
   return len;
 };