diff --git a/package.json b/package.json
index 9bdf131b5..2d9c5c899 100644
--- a/package.json
+++ b/package.json
@@ -100,7 +100,6 @@
     "eslint-plugin-react": "^6.8.0",
     "express": "^4.14.1",
     "flow-bin": "^0.47.0",
-    "flow-copy-source": "^1.1.0",
     "flow-watch": "^1.1.1",
     "jest": "^19.0.2",
     "jsdom": "^9.10.0",
diff --git a/yarn.lock b/yarn.lock
index 1f36bdf2c..276317916 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1279,10 +1279,6 @@ camelcase@^1.0.2:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-1.2.1.tgz#9bb5304d2e0b56698b2c758b08a3eaa9daa58a39"
 
-camelcase@^2.0.1:
-  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-2.1.1.tgz#7c1d16d679a1bbe59ca02cacecfb011e201f5a1f"
-
 camelcase@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-3.0.0.tgz#32fc4b9fcdaf845fcdf7e73bb97cac2261f0ab0a"
@@ -1397,7 +1393,7 @@ cliui@^2.1.0:
     right-align "^0.1.1"
     wordwrap "0.0.2"
 
-cliui@^3.0.3, cliui@^3.2.0:
+cliui@^3.2.0:
   version "3.2.0"
   resolved "https://registry.yarnpkg.com/cliui/-/cliui-3.2.0.tgz#120601537a916d29940f934da3b48d585a39213d"
   dependencies:
@@ -2587,15 +2583,6 @@ flow-bin@^0.47.0:
   version "0.47.0"
   resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.47.0.tgz#a2a08ab3e0d1f1cb57d17e27b30b118b62fda367"
 
-flow-copy-source@^1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/flow-copy-source/-/flow-copy-source-1.1.0.tgz#0779692ff81693d304021b2d49753898a0772237"
-  dependencies:
-    fs-extra "^0.26.5"
-    glob "^7.0.0"
-    kefir "^3.2.0"
-    yargs "^3.32.0"
-
 flow-remove-types@^1.1.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/flow-remove-types/-/flow-remove-types-1.2.0.tgz#c285516eabba72177a1b10bfb58f6ffb675a8877"
@@ -2663,7 +2650,7 @@ from@~0:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/from/-/from-0.1.7.tgz#83c60afc58b9c56997007ed1a768b3ab303a44fe"
 
-fs-extra@^0.26.2, fs-extra@^0.26.5:
+fs-extra@^0.26.2:
   version "0.26.7"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-0.26.7.tgz#9ae1fdd94897798edab76d0918cf42d0c3184fa9"
   dependencies:
@@ -3761,12 +3748,6 @@ jsx-ast-utils@^1.0.0, jsx-ast-utils@^1.3.4:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/jsx-ast-utils/-/jsx-ast-utils-1.4.1.tgz#3867213e8dd79bf1e8f2300c0cfc1efb182c0df1"
 
-kefir@^3.2.0:
-  version "3.7.1"
-  resolved "https://registry.yarnpkg.com/kefir/-/kefir-3.7.1.tgz#e77f56feeec46f4a2ee2997e5c3226e904877b5b"
-  dependencies:
-    symbol-observable "^1.0.1"
-
 kind-of@^3.0.2:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-3.1.0.tgz#475d698a5e49ff5e53d14e3e732429dc8bf4cf47"
@@ -6280,10 +6261,6 @@ window-size@0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/window-size/-/window-size-0.1.0.tgz#5438cd2ea93b202efa3a19fe8887aee7c94f9c9d"
 
-window-size@^0.1.4:
-  version "0.1.4"
-  resolved "https://registry.yarnpkg.com/window-size/-/window-size-0.1.4.tgz#f8e1aa1ee5a53ec5bf151ffa09742a6ad7697876"
-
 window-size@^0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/window-size/-/window-size-0.2.0.tgz#b4315bb4214a3d7058ebeee892e13fa24d98b075"
@@ -6381,7 +6358,7 @@ xmldom@0.1.x:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.1.tgz#a5c6d532be656e23db820efb943a1f04998d63af"
 
-y18n@^3.2.0, y18n@^3.2.1:
+y18n@^3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/y18n/-/y18n-3.2.1.tgz#6d15fba884c08679c0d77e88e7759e811e07fa41"
 
@@ -6402,18 +6379,6 @@ yargs-parser@^4.2.0:
   dependencies:
     camelcase "^3.0.0"
 
-yargs@^3.32.0:
-  version "3.32.0"
-  resolved "https://registry.yarnpkg.com/yargs/-/yargs-3.32.0.tgz#03088e9ebf9e756b69751611d2a5ef591482c995"
-  dependencies:
-    camelcase "^2.0.1"
-    cliui "^3.0.3"
-    decamelize "^1.1.1"
-    os-locale "^1.4.0"
-    string-width "^1.0.1"
-    window-size "^0.1.4"
-    y18n "^3.2.0"
-
 yargs@^4.8.0:
   version "4.8.1"
   resolved "https://registry.yarnpkg.com/yargs/-/yargs-4.8.1.tgz#c0c42924ca4aaa6b0e6da1739dfb216439f9ddc0"