diff --git a/package.json b/package.json
index fbf35aa..8dafa22 100644
--- a/package.json
+++ b/package.json
@@ -77,7 +77,7 @@
     "flow-watch": "^1.1.0",
     "husky": "^0.14.3",
     "istanbul": "^0.4.5",
-    "mocha": "^4.1.0",
+    "mocha": "^5.0.0",
     "nyc": "^11.4.1",
     "rimraf": "^2.6.0",
     "semantic-release": "^12.2.2",
diff --git a/yarn.lock b/yarn.lock
index 96d0e15..ff4285c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -108,7 +108,7 @@
 
 "@jedwards1211/eslint-config@^2.0.0":
   version "2.0.0"
-  resolved "https://registry.npmjs.org/@jedwards1211/eslint-config/-/eslint-config-2.0.0.tgz#9a12391cbdfe449983b7a299a9057dc7afa87cdf"
+  resolved "https://registry.yarnpkg.com/@jedwards1211/eslint-config/-/eslint-config-2.0.0.tgz#9a12391cbdfe449983b7a299a9057dc7afa87cdf"
 
 "@marionebl/sander@^0.6.0":
   version "0.6.1"
@@ -3792,9 +3792,9 @@ mkdirp@0.5.1, mkdirp@0.5.x, "mkdirp@>=0.5 0", mkdirp@^0.5.0, mkdirp@^0.5.1:
   dependencies:
     minimist "0.0.8"
 
-mocha@^4.1.0:
-  version "4.1.0"
-  resolved "https://registry.npmjs.org/mocha/-/mocha-4.1.0.tgz#7d86cfbcf35cb829e2754c32e17355ec05338794"
+mocha@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.0.0.tgz#cccac988b0bc5477119cba0e43de7af6d6ad8f4e"
   dependencies:
     browser-stdout "1.3.0"
     commander "2.11.0"