diff --git a/package.json b/package.json
index dfbb70d..888eef8 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
   },
   "dependencies": {
     "broccoli-funnel": "^2.0.1",
-    "broccoli-merge-trees": "^3.0.1",
+    "broccoli-merge-trees": "^4.0.0",
     "broccoli-stew": "^2.0.0",
     "ember-cli-babel": "^6.16.0",
     "ember-get-config": "^0.2.4",
diff --git a/yarn.lock b/yarn.lock
index c98002e..20c4d40 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -95,6 +95,16 @@
   resolved "https://registry.yarnpkg.com/@sindresorhus/is/-/is-0.7.0.tgz#9a06f4f137ee84d7df0460c1fdb1135ffa6c50fd"
   integrity sha512-ONhaKPIufzzrlNbqtWFFd+jlnemX6lJAgq9ZeiZtS7I1PIf/la7CW4m83rTXRnVnsMbW2k56pGYu7AUFJD9Pow==
 
+"@types/minimatch@^3.0.3":
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
+  integrity sha512-tHq6qdbT9U1IRSGf14CL0pUlULksvY9OZ+5eEgl1N7t+OA3tGvNpxJCzuKQlsNgCVwbAs670L1vcVQi8j9HjnA==
+
+"@types/symlink-or-copy@^1.2.0":
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/@types/symlink-or-copy/-/symlink-or-copy-1.2.0.tgz#4151a81b4052c80bc2becbae09f3a9ec010a9c7a"
+  integrity sha512-Lja2xYuuf2B3knEsga8ShbOdsfNOtzT73GyJmZyY7eGl2+ajOqrs8yM5ze0fsSoYwvA6bw7/Qr7OZ7PEEmYwWg==
+
 abbrev@1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/abbrev/-/abbrev-1.1.1.tgz#f8f2c887ad10bf67f634f005b6987fed3179aac8"
@@ -1600,7 +1610,7 @@ broccoli-merge-trees@^2.0.0:
     broccoli-plugin "^1.3.0"
     merge-trees "^1.0.1"
 
-broccoli-merge-trees@^3.0.0, broccoli-merge-trees@^3.0.1:
+broccoli-merge-trees@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/broccoli-merge-trees/-/broccoli-merge-trees-3.0.1.tgz#545dfe9f695cec43372b3ee7e63c7203713ea554"
   integrity sha512-EFPBLbCoyCLdjJx0lxn+acWXK/GAZesXokS4OsF7HuB+WdnV76HVJPdfwp9TaXaUkrtb7eU+ymh9tY9wOGQjMQ==
@@ -1608,6 +1618,14 @@ broccoli-merge-trees@^3.0.0, broccoli-merge-trees@^3.0.1:
     broccoli-plugin "^1.3.0"
     merge-trees "^2.0.0"
 
+broccoli-merge-trees@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/broccoli-merge-trees/-/broccoli-merge-trees-4.0.0.tgz#57c7993cc74bf16efed8df7a5188a0202a70216d"
+  integrity sha512-FJ1dTqxzDmpqbQFxuhicPbA6URV0D1XCKHFIvKwi6Y70pxuYLMpyRfjNv6iNSwSq/juxGubunKiLb8U2dM+a2A==
+  dependencies:
+    broccoli-plugin "^3.1.0"
+    merge-trees "^2.0.0"
+
 broccoli-middleware@^2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/broccoli-middleware/-/broccoli-middleware-2.0.1.tgz#093314f13e52fad7fa8c4254a4e4a4560c857a65"
@@ -1635,11 +1653,28 @@ broccoli-module-unification-reexporter@^1.0.0:
     mkdirp "^0.5.1"
     walk-sync "^0.3.2"
 
+broccoli-node-api@^1.6.0, broccoli-node-api@^1.7.0:
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/broccoli-node-api/-/broccoli-node-api-1.7.0.tgz#391aa6edecd2a42c63c111b4162956b2fa288cb6"
+  integrity sha512-QIqLSVJWJUVOhclmkmypJJH9u9s/aWH4+FH6Q6Ju5l+Io4dtwqdPUNmDfw40o6sxhbZHhqGujDJuHTML1wG8Yw==
+
 broccoli-node-info@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/broccoli-node-info/-/broccoli-node-info-1.1.0.tgz#3aa2e31e07e5bdb516dd25214f7c45ba1c459412"
   integrity sha1-OqLjHgflvbUW3SUhT3xFuhxFlBI=
 
+broccoli-node-info@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/broccoli-node-info/-/broccoli-node-info-2.1.0.tgz#ca84560e8570ff78565bea1699866ddbf58ad644"
+  integrity sha512-l6qDuboJThHfRVVWQVaTs++bFdrFTP0gJXgsWenczc1PavRVUmL1Eyb2swTAXXMpDOnr2zhNOBLx4w9AxkqbPQ==
+
+broccoli-output-wrapper@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/broccoli-output-wrapper/-/broccoli-output-wrapper-2.0.0.tgz#f1e0b9b2f259a67fd41a380141c3c20b096828e6"
+  integrity sha512-V/ozejo+snzNf75i/a6iTmp71k+rlvqjE3+jYfimuMwR1tjNNRdtfno+NGNQB2An9bIAeqZnKhMDurAznHAdtA==
+  dependencies:
+    heimdalljs-logger "^0.1.10"
+
 broccoli-persistent-filter@^1.1.6, broccoli-persistent-filter@^1.4.0, broccoli-persistent-filter@^1.4.3:
   version "1.4.3"
   resolved "https://registry.yarnpkg.com/broccoli-persistent-filter/-/broccoli-persistent-filter-1.4.3.tgz#3511bc52fc53740cda51621f58a28152d9911bc1"
@@ -1679,6 +1714,19 @@ broccoli-plugin@^1.0.0, broccoli-plugin@^1.1.0, broccoli-plugin@^1.2.0, broccoli
     rimraf "^2.3.4"
     symlink-or-copy "^1.1.8"
 
+broccoli-plugin@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/broccoli-plugin/-/broccoli-plugin-3.1.0.tgz#54ba6dd90a42ec3db5624063292610e326b1e542"
+  integrity sha512-7w7FP8WJYjLvb0eaw27LO678TGGaom++49O1VYIuzjhXjK5kn2+AMlDm7CaUFw4F7CLGoVQeZ84d8gICMJa4lA==
+  dependencies:
+    broccoli-node-api "^1.6.0"
+    broccoli-output-wrapper "^2.0.0"
+    fs-merger "^3.0.1"
+    promise-map-series "^0.2.1"
+    quick-temp "^0.1.3"
+    rimraf "^2.3.4"
+    symlink-or-copy "^1.1.8"
+
 broccoli-slow-trees@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/broccoli-slow-trees/-/broccoli-slow-trees-3.0.1.tgz#9bf2a9e2f8eb3ed3a3f2abdde988da437ccdc9b4"
@@ -3251,6 +3299,11 @@ ensure-posix-path@^1.0.0, ensure-posix-path@^1.0.1, ensure-posix-path@^1.0.2:
   resolved "https://registry.yarnpkg.com/ensure-posix-path/-/ensure-posix-path-1.0.2.tgz#a65b3e42d0b71cfc585eb774f9943c8d9b91b0c2"
   integrity sha1-pls+QtC3HPxYXrd0+ZQ8jZuRsMI=
 
+ensure-posix-path@^1.1.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/ensure-posix-path/-/ensure-posix-path-1.1.1.tgz#3c62bdb19fa4681544289edb2b382adc029179ce"
+  integrity sha512-VWU0/zXzVbeJNXvME/5EmLuEj2TauvoaTz6aFYK1Z92JCBlDlZ3Gu0tuGR42kpW1754ywTs+QB0g5TP0oj9Zaw==
+
 entities@~1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/entities/-/entities-1.1.1.tgz#6e5c2d0a5621b5dadaecef80b90edfb5cd7772f0"
@@ -4044,6 +4097,27 @@ fs-extra@^7.0.0:
     jsonfile "^4.0.0"
     universalify "^0.1.0"
 
+fs-extra@^8.0.1:
+  version "8.1.0"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-8.1.0.tgz#49d43c45a88cd9677668cb7be1b46efdb8d2e1c0"
+  integrity sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==
+  dependencies:
+    graceful-fs "^4.2.0"
+    jsonfile "^4.0.0"
+    universalify "^0.1.0"
+
+fs-merger@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/fs-merger/-/fs-merger-3.0.1.tgz#4fba891e1ac83ce1ea4261b91fee475aaf628cb2"
+  integrity sha512-0DDF7GDMm4roej5N6Z7ZNC2y2VdZdYQtHm32wWluSONyxUMqIAWyD73v0S12GkqO416BGqSHr2tjU4hmIlbylw==
+  dependencies:
+    broccoli-node-api "^1.7.0"
+    broccoli-node-info "^2.1.0"
+    fs-extra "^8.0.1"
+    fs-tree-diff "^2.0.1"
+    rimraf "^2.6.3"
+    walk-sync "^2.0.2"
+
 fs-minipass@^1.2.5:
   version "1.2.5"
   resolved "https://registry.yarnpkg.com/fs-minipass/-/fs-minipass-1.2.5.tgz#06c277218454ec288df77ada54a03b8702aacb9d"
@@ -4071,6 +4145,17 @@ fs-tree-diff@^0.5.7:
     path-posix "^1.0.0"
     symlink-or-copy "^1.1.8"
 
+fs-tree-diff@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/fs-tree-diff/-/fs-tree-diff-2.0.1.tgz#343e4745ab435ec39ebac5f9059ad919cd034afa"
+  integrity sha512-x+CfAZ/lJHQqwlD64pYM5QxWjzWhSjroaVsr8PW831zOApL55qPibed0c+xebaLWVr2BnHFoHdrwOv8pzt8R5A==
+  dependencies:
+    "@types/symlink-or-copy" "^1.2.0"
+    heimdalljs-logger "^0.1.7"
+    object-assign "^4.1.0"
+    path-posix "^1.0.0"
+    symlink-or-copy "^1.1.8"
+
 fs-updater@^1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/fs-updater/-/fs-updater-1.0.4.tgz#2329980f99ae9176e9a0e84f7637538a182ce63b"
@@ -4333,6 +4418,18 @@ glob@^7.0.3, glob@^7.0.4, glob@^7.0.5, glob@^7.1.1, glob@^7.1.2:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
+glob@^7.1.3:
+  version "7.1.6"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.6.tgz#141f33b81a7c2492e125594307480c46679278a6"
+  integrity sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==
+  dependencies:
+    fs.realpath "^1.0.0"
+    inflight "^1.0.4"
+    inherits "2"
+    minimatch "^3.0.4"
+    once "^1.3.0"
+    path-is-absolute "^1.0.0"
+
 glob@~6.0.3:
   version "6.0.4"
   resolved "https://registry.yarnpkg.com/glob/-/glob-6.0.4.tgz#0f08860f6a155127b2fadd4f9ce24b1aab6e4d22"
@@ -4444,6 +4541,11 @@ graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.3, graceful-fs@^4.1.6,
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
   integrity sha1-Dovf5NHduIVNZOBOp8AOKgJuVlg=
 
+graceful-fs@^4.2.0:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.3.tgz#4a12ff1b60376ef09862c2093edd908328be8423"
+  integrity sha512-a30VEBm4PEdx1dRB7MFK7BejejvCvBronbLjht+sHuGYj8PHs7M/5Z+rt5lw551vZ7yfTCj4Vuyy3mSJytDWRQ==
+
 "graceful-readlink@>= 1.0.0":
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/graceful-readlink/-/graceful-readlink-1.0.1.tgz#4cafad76bc62f02fa039b2f94e9a3dd3a391a725"
@@ -4651,6 +4753,14 @@ heimdalljs-graph@^0.3.4:
   resolved "https://registry.yarnpkg.com/heimdalljs-graph/-/heimdalljs-graph-0.3.5.tgz#420fbbc8fc3aec5963ddbbf1a5fb47921c4a5927"
   integrity sha512-szOy9WZUc7eUInEBQEsoa1G2d+oYHrn6ndZPf76eh8A9ID1zWUCEEsxP3F+CvQx9+EDrg1srdyLUmfVAr8EB4g==
 
+heimdalljs-logger@^0.1.10:
+  version "0.1.10"
+  resolved "https://registry.yarnpkg.com/heimdalljs-logger/-/heimdalljs-logger-0.1.10.tgz#90cad58aabb1590a3c7e640ddc6a4cd3a43faaf7"
+  integrity sha512-pO++cJbhIufVI/fmB/u2Yty3KJD0TqNPecehFae0/eps0hkZ3b4Zc/PezUMOpYuHFQbA7FxHZxa305EhmjLj4g==
+  dependencies:
+    debug "^2.2.0"
+    heimdalljs "^0.2.6"
+
 heimdalljs-logger@^0.1.7, heimdalljs-logger@^0.1.9:
   version "0.1.9"
   resolved "https://registry.yarnpkg.com/heimdalljs-logger/-/heimdalljs-logger-0.1.9.tgz#d76ada4e45b7bb6f786fc9c010a68eb2e2faf176"
@@ -4666,7 +4776,7 @@ heimdalljs@^0.2.0, heimdalljs@^0.2.1, heimdalljs@^0.2.3:
   dependencies:
     rsvp "~3.2.1"
 
-heimdalljs@^0.2.5:
+heimdalljs@^0.2.5, heimdalljs@^0.2.6:
   version "0.2.6"
   resolved "https://registry.yarnpkg.com/heimdalljs/-/heimdalljs-0.2.6.tgz#b0eebabc412813aeb9542f9cc622cb58dbdcd9fe"
   integrity sha512-o9bd30+5vLBvBtzCPwwGqpry2+n0Hi6H1+qwt6y+0kwRHGGF8TFIhJPmnuM0xO97zaKrDZMwO/V56fAnn8m/tA==
@@ -6186,6 +6296,14 @@ matcher-collection@^1.0.0, matcher-collection@^1.0.4, matcher-collection@^1.0.5:
   dependencies:
     minimatch "^3.0.2"
 
+matcher-collection@^2.0.0:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/matcher-collection/-/matcher-collection-2.0.1.tgz#90be1a4cf58d6f2949864f65bb3b0f3e41303b29"
+  integrity sha512-daE62nS2ZQsDg9raM0IlZzLmI2u+7ZapXBwdoeBUKAYERPDDIc0qNqA8E0Rp2D+gspKR7BgIFP52GeujaGXWeQ==
+  dependencies:
+    "@types/minimatch" "^3.0.3"
+    minimatch "^3.0.2"
+
 md5-hex@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/md5-hex/-/md5-hex-2.0.0.tgz#d0588e9f1c74954492ecd24ac0ac6ce997d92e33"
@@ -7873,6 +7991,13 @@ rimraf@2, rimraf@^2.2.8, rimraf@^2.3.2, rimraf@^2.3.4, rimraf@^2.4.3, rimraf@^2.
   dependencies:
     glob "^7.0.5"
 
+rimraf@^2.6.3:
+  version "2.7.1"
+  resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.7.1.tgz#35797f13a7fdadc566142c29d4f07ccad483e3ec"
+  integrity sha512-uWjbaKIK3T1OSVptzX7Nl6PvQ3qAGtKEtVRjRuazjfL3Bx5eI409VZSqgND+4UNnmzLVdPj9FqFJNPqBZFve4w==
+  dependencies:
+    glob "^7.1.3"
+
 rimraf@~2.2.6:
   version "2.2.8"
   resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.2.8.tgz#e439be2aaee327321952730f99a8929e4fc50582"
@@ -9110,6 +9235,15 @@ walk-sync@^0.3.3:
     ensure-posix-path "^1.0.0"
     matcher-collection "^1.0.0"
 
+walk-sync@^2.0.2:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/walk-sync/-/walk-sync-2.0.2.tgz#5ea8a28377c8be68c92d50f4007ea381725da14b"
+  integrity sha512-dCZkrxfHjPn7tIvdYrX3uMD/R0beVrHpA8lROQ5wWrl8psJgR6xwCkwqTFes0dNujbS2o/ITpvSYgIFsLsf13A==
+  dependencies:
+    "@types/minimatch" "^3.0.3"
+    ensure-posix-path "^1.1.0"
+    matcher-collection "^2.0.0"
+
 walker@~1.0.5:
   version "1.0.7"
   resolved "https://registry.yarnpkg.com/walker/-/walker-1.0.7.tgz#2f7f9b8fd10d677262b18a884e28d19618e028fb"