diff --git a/index.js b/index.js
index 9784afa..8862e76 100644
--- a/index.js
+++ b/index.js
@@ -26,11 +26,17 @@ module.exports = {
   },
 
   treeForAddon: function(tree) {
+    if (!tree) {
+      return;
+    }
     var fastbootTree = require('ember-cli-fastboot-addon').fastbootTree;
     return this._super.treeForAddon.call(this, fastbootTree(tree));
   },
 
   treeForApp: function(tree) {
+    if (!tree) {
+      return;
+    }
     var fastbootTree = require('ember-cli-fastboot-addon').fastbootTree;
     return fastbootTree(tree);
   },