diff --git a/lib/protocol.js b/lib/protocol.js
index 2c5598c..a7c3b7a 100644
--- a/lib/protocol.js
+++ b/lib/protocol.js
@@ -541,7 +541,7 @@ EntityMetadataWriter.prototype.write = function(buffer, offset) {
 
 function ObjectDataWriter(value) {
   this.value = value;
-  this.size = value === 0 ? 4 : 10;
+  this.size = value.intField === 0 ? 4 : 10;
 }
 
 ObjectDataWriter.prototype.write = function(buffer, offset) {