diff --git a/src/builder.js b/src/builder.js
index 80556b2..d6a56b0 100644
--- a/src/builder.js
+++ b/src/builder.js
@@ -103,7 +103,7 @@ class TreeBuilder {
return d.x - d.cWidth / 2 + 'px';
})
.attr('y', function(d) {
- return d.y - d.cHeight / 2 + 'px';
+ return Math.round(d.y - d.cHeight / 2) + 'px';
})
.attr('width', function(d) {
return d.cWidth + 'px';
diff --git a/test/demo/index.html b/test/demo/index.html
index 3052364..c0a641f 100644
--- a/test/demo/index.html
+++ b/test/demo/index.html
@@ -1,4 +1,5 @@
+