diff --git a/lib/node.js b/lib/node.js
index 343c0c6..8bb6807 100644
--- a/lib/node.js
+++ b/lib/node.js
@@ -293,7 +293,10 @@ Node.prototype.txDensityChart = function()
 {
 	return txDensity = _.map(this.blocks, function(block)
 	{
-		return block.transactions.length;
+		if(typeof block.transactions !== 'undefined')
+			return block.transactions.length;
+
+		return 0;
 	});
 }