diff --git a/lib/network/Edge.js b/lib/network/Edge.js
index 5a32d1ee..c5fdf072 100644
--- a/lib/network/Edge.js
+++ b/lib/network/Edge.js
@@ -1,4 +1,5 @@
 var util = require('../util');
+var Node = require('./Node');
 
 /**
  * @class Edge
diff --git a/lib/network/mixins/ManipulationMixin.js b/lib/network/mixins/ManipulationMixin.js
index 5348c777..2413ec3f 100644
--- a/lib/network/mixins/ManipulationMixin.js
+++ b/lib/network/mixins/ManipulationMixin.js
@@ -1,4 +1,6 @@
 var util = require('../../util');
+var Node = require('../Node');
+var Edge = require('../Edge');
 
 /**
  * clears the toolbar div element of children