diff --git a/static/js/graphing.js b/static/js/graphing.js
index 8e710e9aa..02a4d3fd3 100644
--- a/static/js/graphing.js
+++ b/static/js/graphing.js
@@ -909,6 +909,8 @@ FileTreeBase.prototype.calculateDimensions_ = function(container) {
  * Updates the dimensions of the tree.
  */
 FileTreeBase.prototype.updateDimensions_ = function() {
+  if (!this.rootSvg_) { return; }
+
   var container = this.container_;
   var dimensions = this.calculateDimensions_(container);