diff --git a/package.json b/package.json
index 21758eb..88978ab 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
   },
   "devDependencies": {
     "@types/qunit": "^2.0.31",
-    "broccoli-concat": "^3.2.2",
+    "broccoli-concat": "^4.0.0",
     "broccoli-debug": "^0.6.4",
     "broccoli-funnel": "^2.0.1",
     "broccoli-merge-trees": "^3.0.0",
diff --git a/yarn.lock b/yarn.lock
index e2a6843..dee4174 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -773,6 +773,24 @@ broccoli-concat@^3.2.2:
     lodash.uniq "^4.2.0"
     walk-sync "^0.3.1"
 
+broccoli-concat@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/broccoli-concat/-/broccoli-concat-4.0.0.tgz#dc2fe95683b36ef0f9114134afa6ae06a7c430ca"
+  integrity sha512-s8sCP5A8zcomrvue15ToOIxi5CKGOtg+oIGUYdN4EdYTeD6d/mptD9v+38MigOPt+Jgc6tcLloFVZSI+9+FLEg==
+  dependencies:
+    broccoli-debug "^0.6.5"
+    broccoli-kitchen-sink-helpers "^0.3.1"
+    broccoli-plugin "^1.3.0"
+    ensure-posix-path "^1.0.2"
+    fast-sourcemap-concat "^1.4.0"
+    find-index "^1.1.0"
+    fs-extra "^4.0.3"
+    fs-tree-diff "^0.5.7"
+    lodash.merge "^4.6.2"
+    lodash.omit "^4.1.0"
+    lodash.uniq "^4.2.0"
+    walk-sync "^0.3.2"
+
 broccoli-config-loader@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/broccoli-config-loader/-/broccoli-config-loader-1.0.1.tgz#d10aaf8ebc0cb45c1da5baa82720e1d88d28c80a"
@@ -799,6 +817,18 @@ broccoli-debug@^0.6.1, broccoli-debug@^0.6.3, broccoli-debug@^0.6.4:
     symlink-or-copy "^1.1.8"
     tree-sync "^1.2.2"
 
+broccoli-debug@^0.6.5:
+  version "0.6.5"
+  resolved "https://registry.yarnpkg.com/broccoli-debug/-/broccoli-debug-0.6.5.tgz#164a5cdafd8936e525e702bf8f91f39d758e2e78"
+  integrity sha512-RIVjHvNar9EMCLDW/FggxFRXqpjhncM/3qq87bn/y+/zR9tqEkHvTqbyOc4QnB97NO2m6342w4wGkemkaeOuWg==
+  dependencies:
+    broccoli-plugin "^1.2.1"
+    fs-tree-diff "^0.5.2"
+    heimdalljs "^0.2.1"
+    heimdalljs-logger "^0.1.7"
+    symlink-or-copy "^1.1.8"
+    tree-sync "^1.2.2"
+
 broccoli-funnel-reducer@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/broccoli-funnel-reducer/-/broccoli-funnel-reducer-1.0.0.tgz#11365b2a785aec9b17972a36df87eef24c5cc0ea"
@@ -2339,6 +2369,20 @@ fast-sourcemap-concat@^1.0.1:
     source-map-url "^0.3.0"
     sourcemap-validator "^1.0.5"
 
+fast-sourcemap-concat@^1.4.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/fast-sourcemap-concat/-/fast-sourcemap-concat-1.4.0.tgz#122c330d4a2afaff16ad143bc9674b87cd76c8ad"
+  integrity sha512-x90Wlx/2C83lfyg7h4oguTZN4MyaVfaiUSJQNpU+YEA0Odf9u659Opo44b0LfoVg9G/bOE++GdID/dkyja+XcA==
+  dependencies:
+    chalk "^2.0.0"
+    fs-extra "^5.0.0"
+    heimdalljs-logger "^0.1.9"
+    memory-streams "^0.1.3"
+    mkdirp "^0.5.0"
+    source-map "^0.4.2"
+    source-map-url "^0.3.0"
+    sourcemap-validator "^1.1.0"
+
 faye-websocket@~0.10.0:
   version "0.10.0"
   resolved "https://registry.yarnpkg.com/faye-websocket/-/faye-websocket-0.10.0.tgz#4e492f8d04dfb6f89003507f6edbf2d501e7c6f4"
@@ -2525,9 +2569,19 @@ fs-extra@^2.0.0:
     graceful-fs "^4.1.2"
     jsonfile "^2.1.0"
 
-fs-extra@^4.0.0, fs-extra@^4.0.1:
+fs-extra@^4.0.0, fs-extra@^4.0.1, fs-extra@^4.0.3:
   version "4.0.3"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-4.0.3.tgz#0d852122e5bc5beb453fb028e9c0c9bf36340c94"
+  integrity sha512-q6rbdDd1o2mAnQreO7YADIxf/Whx4AHBiRf6d+/cVT8h44ss+lHgxf1FemcqDnQt9X3ct4McHr+JMGlYSsK7Cg==
+  dependencies:
+    graceful-fs "^4.1.2"
+    jsonfile "^4.0.0"
+    universalify "^0.1.0"
+
+fs-extra@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-5.0.0.tgz#414d0110cdd06705734d055652c5411260c31abd"
+  integrity sha512-66Pm4RYbjzdyeuqudYqhFiNBbCIuI9kgRqLPSHIlXHidW8NIQtVdkM1yeZ4lXwuhbTETv3EUGMNHAAw6hiundQ==
   dependencies:
     graceful-fs "^4.1.2"
     jsonfile "^4.0.0"
@@ -3763,14 +3817,14 @@ lodash._objecttypes@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash._objecttypes/-/lodash._objecttypes-2.3.0.tgz#6a3ea3987dd6eeb8021b2d5c9c303549cc2bae1e"
 
+lodash._reinterpolate@^3.0.0, lodash._reinterpolate@~3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/lodash._reinterpolate/-/lodash._reinterpolate-3.0.0.tgz#0ccf2d89166af03b3663c796538b75ac6e114d9d"
+
 lodash._reinterpolate@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash._reinterpolate/-/lodash._reinterpolate-2.3.0.tgz#03ee9d85c0e55cbd590d71608a295bdda51128ec"
 
-lodash._reinterpolate@~3.0.0:
-  version "3.0.0"
-  resolved "https://registry.yarnpkg.com/lodash._reinterpolate/-/lodash._reinterpolate-3.0.0.tgz#0ccf2d89166af03b3663c796538b75ac6e114d9d"
-
 lodash._renative@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash._renative/-/lodash._renative-2.3.0.tgz#77d8edd4ced26dd5971f9e15a5f772e4e317fbd3"
@@ -3864,6 +3918,11 @@ lodash.flattendeep@^4.4.0:
   resolved "https://registry.yarnpkg.com/lodash.flattendeep/-/lodash.flattendeep-4.4.0.tgz#fb030917f86a3134e5bc9bec0d69e0013ddfedb2"
   integrity sha1-+wMJF/hqMTTlvJvsDWngAT3f7bI=
 
+lodash.foreach@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.foreach/-/lodash.foreach-4.5.0.tgz#1a6a35eace401280c7f06dddec35165ab27e3e53"
+  integrity sha1-Gmo16s5AEoDH8G3d7DUWWrJ+PlM=
+
 lodash.foreach@~2.3.x:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash.foreach/-/lodash.foreach-2.3.0.tgz#083404c91e846ee77245fdf9d76519c68b2af168"
@@ -3921,6 +3980,11 @@ lodash.merge@^4.3.0, lodash.merge@^4.4.0, lodash.merge@^4.6.0:
   version "4.6.1"
   resolved "https://registry.yarnpkg.com/lodash.merge/-/lodash.merge-4.6.1.tgz#adc25d9cb99b9391c59624f379fbba60d7111d54"
 
+lodash.merge@^4.6.2:
+  version "4.6.2"
+  resolved "https://registry.yarnpkg.com/lodash.merge/-/lodash.merge-4.6.2.tgz#558aa53b43b661e1925a0afdfa36a9a1085fe57a"
+  integrity sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==
+
 lodash.noop@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash.noop/-/lodash.noop-2.3.0.tgz#3059d628d51bbf937cd2a0b6fc3a7f212a669c2c"
@@ -3946,6 +4010,14 @@ lodash.template@^4.0.2, lodash.template@^4.2.5:
     lodash._reinterpolate "~3.0.0"
     lodash.templatesettings "^4.0.0"
 
+lodash.template@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.template/-/lodash.template-4.5.0.tgz#f976195cf3f347d0d5f52483569fe8031ccce8ab"
+  integrity sha512-84vYFxIkmidUiFxidA/KjjH9pAycqW+h980j7Fuz5qxRtO9pgB7MDFTdys1N7A5mcucRiDyEq4fusljItR1T/A==
+  dependencies:
+    lodash._reinterpolate "^3.0.0"
+    lodash.templatesettings "^4.0.0"
+
 lodash.template@~2.3.x:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/lodash.template/-/lodash.template-2.3.0.tgz#4e3e29c433b4cfea675ec835e6f12391c61fd22b"
@@ -4137,9 +4209,10 @@ mem@^4.0.0:
     mimic-fn "^1.0.0"
     p-is-promise "^2.0.0"
 
-memory-streams@^0.1.0:
+memory-streams@^0.1.0, memory-streams@^0.1.3:
   version "0.1.3"
   resolved "https://registry.yarnpkg.com/memory-streams/-/memory-streams-0.1.3.tgz#d9b0017b4b87f1d92f55f2745c9caacb1dc93ceb"
+  integrity sha512-qVQ/CjkMyMInPaaRMrwWNDvf6boRZXaT/DbQeMYcCWuXPEBf1v8qChOc9OlEVQp2uOvRXa1Qu30fLmKhY6NipA==
   dependencies:
     readable-stream "~1.0.2"
 
@@ -5603,6 +5676,16 @@ sourcemap-validator@^1.0.5:
     lodash.template "~2.3.x"
     source-map "~0.1.x"
 
+sourcemap-validator@^1.1.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/sourcemap-validator/-/sourcemap-validator-1.1.1.tgz#3d7d8a399ccab09c1fedc510d65436e25b1c386b"
+  integrity sha512-pq6y03Vs6HUaKo9bE0aLoksAcpeOo9HZd7I8pI6O480W/zxNZ9U32GfzgtPP0Pgc/K1JHna569nAbOk3X8/Qtw==
+  dependencies:
+    jsesc "~0.3.x"
+    lodash.foreach "^4.5.0"
+    lodash.template "^4.5.0"
+    source-map "~0.1.x"
+
 spawn-args@^0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/spawn-args/-/spawn-args-0.2.0.tgz#fb7d0bd1d70fd4316bd9e3dec389e65f9d6361bb"