diff --git a/lib/protocol.js b/lib/protocol.js
index 2adac4f..4684e1e 100644
--- a/lib/protocol.js
+++ b/lib/protocol.js
@@ -623,11 +623,11 @@ function readObjectData(buffer, offset) {
 function readMapChunkBulk (buffer, offset) {
   var cursor = offset + 7;
   if (cursor > buffer.length) return null;
-  var chunkCount = buffer.readInt16BE(offset);
+  var chunkColumnCount = buffer.readInt16BE(offset);
   var dataSize = buffer.readInt32BE(offset + 2);
   var skyLightSent = !!buffer.readInt8(offset + 6);
 
-  var cursorEnd = cursor + dataSize + 12 * chunkCount;
+  var cursorEnd = cursor + dataSize + 12 * chunkColumnCount;
   if (cursorEnd > buffer.length) return null;
 
   var compressedChunkDataEnd = cursor + dataSize;
@@ -636,7 +636,7 @@ function readMapChunkBulk (buffer, offset) {
 
   var meta = [];
   var i, chunkX, chunkZ, bitMap, addBitMap;
-  for (i = 0; i < chunkCount; ++i) {
+  for (i = 0; i < chunkColumnCount; ++i) {
     chunkX = buffer.readInt32BE(cursor);
     cursor += 4;
     chunkZ = buffer.readInt32BE(cursor);
@@ -654,10 +654,11 @@ function readMapChunkBulk (buffer, offset) {
     });
   }
 
+  assert.strictEqual(chunkColumnCount, meta.length);
+
   return {
     value: {
       skyLightSent: skyLightSent,
-      chunkCount: chunkCount,
       compressedChunkData: compressedChunkData,
       meta: meta,
     },