diff --git a/package.json b/package.json
index 0d7bff0..baa0264 100644
--- a/package.json
+++ b/package.json
@@ -46,6 +46,6 @@
   "devDependencies": {
     "jshint": "2.9.5",
     "should": "13.1.2",
-    "mocha": "4.0.1"
+    "mocha": "5.0.3"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index 32bbceb..ebfb4f0 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -148,9 +148,9 @@ brace-expansion@^1.1.7:
     balanced-match "^1.0.0"
     concat-map "0.0.1"
 
-browser-stdout@1.3.0:
-  version "1.3.0"
-  resolved "https://registry.yarnpkg.com/browser-stdout/-/browser-stdout-1.3.0.tgz#f351d32969d32fa5d7a5567154263d928ae3bd1f"
+browser-stdout@1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/browser-stdout/-/browser-stdout-1.3.1.tgz#baa559ee14ced73452229bad7326467c61fabd60"
 
 browserslist@^2.4.0:
   version "2.4.0"
@@ -428,9 +428,9 @@ delegates@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/delegates/-/delegates-1.0.0.tgz#84c6e159b81904fdca59a0ef44cd870d31250f9a"
 
-diff@3.3.1:
-  version "3.3.1"
-  resolved "https://registry.yarnpkg.com/diff/-/diff-3.3.1.tgz#aa8567a6eed03c531fc89d3f711cd0e5259dec75"
+diff@3.5.0:
+  version "3.5.0"
+  resolved "https://registry.yarnpkg.com/diff/-/diff-3.5.0.tgz#800c0dd1e0a8bfbc95835c202ad220fe317e5a12"
 
 doctypes@^1.1.0:
   version "1.1.0"
@@ -1064,14 +1064,14 @@ 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@4.0.1:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/mocha/-/mocha-4.0.1.tgz#0aee5a95cf69a4618820f5e51fa31717117daf1b"
+mocha@5.0.3:
+  version "5.0.3"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.0.3.tgz#0a95a6ddea9073239851a3a26ffc9c8d679c757a"
   dependencies:
-    browser-stdout "1.3.0"
+    browser-stdout "1.3.1"
     commander "2.11.0"
     debug "3.1.0"
-    diff "3.3.1"
+    diff "3.5.0"
     escape-string-regexp "1.0.5"
     glob "7.1.2"
     growl "1.10.3"