diff --git a/package.json b/package.json
index c2343c1..1a695be 100644
--- a/package.json
+++ b/package.json
@@ -67,7 +67,7 @@
   "devDependencies": {
     "babel-preset-env": "^1.6.1",
     "js-devbox": "^5.0.0",
-    "mocha": "^4.0.1",
+    "mocha": "^5.0.2",
     "nyc": "^11.4.1",
     "proxyquire": "^1.7.11",
     "sinon": "^4.1.3"
diff --git a/yarn.lock b/yarn.lock
index 535a64c..6f0317c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -895,9 +895,9 @@ browser-resolve@^1.11.2:
   dependencies:
     resolve "1.1.7"
 
-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@^2.1.2:
   version "2.10.0"
@@ -1290,14 +1290,10 @@ detect-newline@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/detect-newline/-/detect-newline-2.1.0.tgz#f41f1c10be4b00e87b5f13da680759f2c5bfd3e2"
 
-diff@3.3.1:
+diff@3.3.1, diff@^3.1.0, diff@^3.2.0:
   version "3.3.1"
   resolved "https://registry.yarnpkg.com/diff/-/diff-3.3.1.tgz#aa8567a6eed03c531fc89d3f711cd0e5259dec75"
 
-diff@^3.1.0, diff@^3.2.0:
-  version "3.4.0"
-  resolved "https://registry.yarnpkg.com/diff/-/diff-3.4.0.tgz#b1d85507daf3964828de54b37d0d73ba67dda56c"
-
 doctrine@1.5.0:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/doctrine/-/doctrine-1.5.0.tgz#379dce730f6166f76cefa4e6707a159b02c5a6fa"
@@ -1594,14 +1590,10 @@ extglob@^0.3.1:
   dependencies:
     is-extglob "^1.0.0"
 
-extsprintf@1.3.0:
+extsprintf@1.3.0, extsprintf@^1.2.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.3.0.tgz#96918440e3041a7a414f8c52e3c574eb3c3e1e05"
 
-extsprintf@^1.2.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.4.0.tgz#e2689f8f356fad62cca65a3a91c5df5f9551692f"
-
 fast-deep-equal@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fast-deep-equal/-/fast-deep-equal-1.0.0.tgz#96256a3bc975595eb36d82e9929d060d893439ff"
@@ -3110,11 +3102,11 @@ mkdirp@0.5.1, "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@^5.0.2:
+  version "5.0.2"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.0.2.tgz#caab0b813575141c5690c37d53c894b605ae60b5"
   dependencies:
-    browser-stdout "1.3.0"
+    browser-stdout "1.3.1"
     commander "2.11.0"
     debug "3.1.0"
     diff "3.3.1"