diff --git a/package.json b/package.json
index 6e3c45f..efd90be 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "eslint-plugin-promise": "^3.6.0",
     "eslint-plugin-standard": "^3.0.1",
     "lerna": "^2.0.0",
-    "mocha": "^4.0.1",
+    "mocha": "^5.2.0",
     "mocha-lcov-reporter": "^1.3.0",
     "nyc": "^11.3.0",
     "remark": "^8.0.0",
diff --git a/yarn.lock b/yarn.lock
index 4ab7556..83da314 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -765,9 +765,9 @@ braces@^1.8.2:
     preserve "^0.2.0"
     repeat-element "^1.1.2"
 
-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"
 
 builtin-modules@^1.0.0, builtin-modules@^1.1.1:
   version "1.1.1"
@@ -1011,7 +1011,11 @@ command-join@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/command-join/-/command-join-2.0.0.tgz#52e8b984f4872d952ff1bdc8b98397d27c7144cf"
 
-commander@2.11.0, commander@^2.8.1, commander@^2.9.0:
+commander@2.15.1:
+  version "2.15.1"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.15.1.tgz#df46e867d0fc2aec66a34662b406a9ccafff5b0f"
+
+commander@^2.8.1, commander@^2.9.0:
   version "2.11.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.11.0.tgz#157152fd1e7a6c8d98a5b715cf376df928004563"
 
@@ -1440,9 +1444,9 @@ detect-indent@^5.0.0:
   version "5.0.0"
   resolved "https://registry.yarnpkg.com/detect-indent/-/detect-indent-5.0.0.tgz#3871cc0a6a002e8c3e5b3cf7f336264675f06b9d"
 
-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"
 
 doctrine@1.5.0:
   version "1.5.0"
@@ -2099,9 +2103,9 @@ graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.4, graceful-fs@^4.1.6,
   version "4.1.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
 
-growl@1.10.3:
-  version "1.10.3"
-  resolved "https://registry.yarnpkg.com/growl/-/growl-1.10.3.tgz#1926ba90cf3edfe2adb4927f5880bc22c66c790f"
+growl@1.10.5:
+  version "1.10.5"
+  resolved "https://registry.yarnpkg.com/growl/-/growl-1.10.5.tgz#f2735dc2283674fa67478b10181059355c369e5e"
 
 handlebars@^4.0.2, handlebars@^4.0.3:
   version "4.0.10"
@@ -2147,6 +2151,10 @@ has-flag@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-2.0.0.tgz#e8207af1cc7b30d446cc70b734b5e8be18f88d51"
 
+has-flag@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-3.0.0.tgz#b5d454dc2199ae225699f3467e5a07f3b955bafd"
+
 has-unicode@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/has-unicode/-/has-unicode-2.0.1.tgz#e0e6fe6a28cf51138855e086d1691e771de2a8b9"
@@ -2955,7 +2963,7 @@ mimic-fn@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/mimic-fn/-/mimic-fn-1.1.0.tgz#e667783d92e89dbd342818b5230b9d62a672ad18"
 
-minimatch@^3.0.0, minimatch@^3.0.2, minimatch@^3.0.3, minimatch@^3.0.4:
+minimatch@3.0.4, minimatch@^3.0.0, minimatch@^3.0.2, minimatch@^3.0.3, minimatch@^3.0.4:
   version "3.0.4"
   resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
   dependencies:
@@ -2983,20 +2991,21 @@ mocha-lcov-reporter@^1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/mocha-lcov-reporter/-/mocha-lcov-reporter-1.3.0.tgz#469bdef4f8afc9a116056f079df6182d0afb0384"
 
-mocha@^4.0.1:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/mocha/-/mocha-4.0.1.tgz#0aee5a95cf69a4618820f5e51fa31717117daf1b"
+mocha@^5.2.0:
+  version "5.2.0"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.2.0.tgz#6d8ae508f59167f940f2b5b3c4a612ae50c90ae6"
   dependencies:
-    browser-stdout "1.3.0"
-    commander "2.11.0"
+    browser-stdout "1.3.1"
+    commander "2.15.1"
     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"
+    growl "1.10.5"
     he "1.1.1"
+    minimatch "3.0.4"
     mkdirp "0.5.1"
-    supports-color "4.4.0"
+    supports-color "5.4.0"
 
 modify-values@^1.0.0:
   version "1.0.0"
@@ -4041,11 +4050,11 @@ strong-log-transformer@^1.0.6:
     moment "^2.6.0"
     through "^2.3.4"
 
-supports-color@4.4.0:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-4.4.0.tgz#883f7ddabc165142b2a61427f3352ded195d1a3e"
+supports-color@5.4.0:
+  version "5.4.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-5.4.0.tgz#1c6b337402c2137605efe19f10fec390f6faab54"
   dependencies:
-    has-flag "^2.0.0"
+    has-flag "^3.0.0"
 
 supports-color@^2.0.0:
   version "2.0.0"