diff --git a/package.json b/package.json
index 2ff8c09..f4986c8 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   "dependencies": {
     "broccoli": "^1.1.0",
     "broccoli-babel-transpiler": "^5.6.1",
-    "broccoli-concat": "^3.0.5",
+    "broccoli-concat": "^4.2.2",
     "broccoli-funnel": "^1.1.0",
     "broccoli-merge-trees": "^1.2.1",
     "broccoli-persistent-filter": "^1.2.12",