diff --git a/static/js/graphing.js b/static/js/graphing.js
index c7f059991..4d2c82ba4 100644
--- a/static/js/graphing.js
+++ b/static/js/graphing.js
@@ -485,6 +485,9 @@ ImageHistoryTree.prototype.buildRoot_ = function() {
     maxChildHeight = Math.max(maxChildHeight, key);
   });
 
+  // Recursively prune the nodes that are not referenced by a tag
+  this.pruneUnreferenced_(root);
+
   // Compact the graph so that any single chain of three (or more) images becomes a collapsed
   // section. We only do this if the max width is > 1 (since for a single width tree, no long
   // chain will hide a branch).
@@ -505,6 +508,23 @@ ImageHistoryTree.prototype.buildRoot_ = function() {
 };
 
 
+/**
+ * Prunes images which are not referenced either directly or indireclty by any tag.
+ */
+ImageHistoryTree.prototype.pruneUnreferenced_ = function(node) {
+  if (node.children) {
+    var surviving_children = []
+    for (var i = 0; i < node.children.length; ++i) {
+      if (!this.pruneUnreferenced_(node.children[i])) {
+        surviving_children.push(node.children[i]);
+      }
+    }
+    node.children = surviving_children;
+  }
+  return (node.children.length == 0 && node.tags.length == 0);
+};
+
+
 /**
  * Determines the height of the tree at its longest chain.
  */