diff --git a/js/lib/d3.dimensions.js b/js/lib/d3.dimensions.js
index d54a05e25..eef257401 100644
--- a/js/lib/d3.dimensions.js
+++ b/js/lib/d3.dimensions.js
@@ -3,8 +3,15 @@ d3.selection.prototype.dimensions = function (dimensions) {
         var node = this.node();
         if (!node) return;
 
-        var cr = node.getBoundingClientRect();
-        return [cr.width, cr.height];
+        var prop = this.property('__dimensions__');
+        if (!prop) {
+            var cr = node.getBoundingClientRect();
+            prop = [cr.width, cr.height];
+            this.property('__dimensions__', prop);
+        }
+        return prop;
     }
+
+    this.property('__dimensions__', [dimensions[0], dimensions[1]]);
     return this.attr({width: dimensions[0], height: dimensions[1]});
 };