diff --git a/static/js/graphing.js b/static/js/graphing.js
index 95d76d1b4..bdd821679 100644
--- a/static/js/graphing.js
+++ b/static/js/graphing.js
@@ -101,6 +101,10 @@ ImageHistoryTree.prototype.draw = function(container) {
                 return html;
             }
 
+            if (!d.image) {
+		return '(This repository is empty)';
+            }
+
             if (d.image.comment) {
                 html += '<span class="comment">' + formatComment(d.image.comment) + '</span>';
             }
@@ -198,7 +202,7 @@ ImageHistoryTree.prototype.buildRoot_ = function() {
     //    "name": "...",
     //    "children": [...]
     //  }
-    var formatted = {};
+    var formatted = {"name": "No images found"};
 
     // Build a node for each image.
     var imageByDBID = {};
@@ -266,8 +270,10 @@ ImageHistoryTree.prototype.buildRoot_ = function() {
  */
 ImageHistoryTree.prototype.determineMaximumHeight_ = function(node) {
    var maxHeight = 0;
-   for (var i = 0; i < node.children.length; ++i) {
-     maxHeight = Math.max(this.determineMaximumHeight_(node.children[i]), maxHeight);
+   if (node.children) {
+     for (var i = 0; i < node.children.length; ++i) {
+       maxHeight = Math.max(this.determineMaximumHeight_(node.children[i]), maxHeight);
+     }
    }
    return maxHeight + 1;
 };
@@ -476,7 +482,7 @@ ImageHistoryTree.prototype.update_ = function(source) {
       .attr("dy", ".35em")
       .attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
       .text(function(d) { return d.name; })
-      .on("click", function(d) { that.changeImage_(d.image.id); })
+      .on("click", function(d) { if (d.image) { that.changeImage_(d.image.id); } })
       .on('mouseover', tip.show)
       .on('mouseout', tip.hide);