diff --git a/lib/util.js b/lib/util.js
index <HASH>..<HASH> 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -1,3 +1,5 @@
+var d3 = require("./d3");
+
 // Public utility functions
 module.exports = {
   isSubgraph: isSubgraph,
Import d3 in lib/util for zoom functions