diff --git a/.travis.yml b/.travis.yml
index be6d7e932c..94aa85770e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -40,9 +40,6 @@ jobs:
     - <<: *node
       node_js: '6'
 
-    - <<: *node
-      node_js: '4'
-
     - script: npm start test.bundle test.browser
       install: npm ci # we need the native modules here
       addons:
@@ -78,9 +75,6 @@ jobs:
     - <<: *smoke
       node_js: '6'
 
-    - <<: *smoke
-      node_js: '4'
-
     - stage: precache
       script: true
 
diff --git a/appveyor.yml b/appveyor.yml
index 31b0ddb83b..2d2e1e459d 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -6,7 +6,6 @@ environment:
     - nodejs_version: '9'
     - nodejs_version: '8'
     - nodejs_version: '6'
-    - nodejs_version: '4'
 install:
   - ps: Install-Product node $env:nodejs_version x64
   - set CI=true
diff --git a/docs/README.md b/docs/README.md
index 56aa8a5c7e..30ef573d79 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -9,7 +9,7 @@
 - Ruby
 - RubyGems
 - Bundler (`gem install bundler`)
-- Node.js v4.0.0 or greater
+- Node.js v6.x or greater
 
 ## Development
 
diff --git a/docs/index.md b/docs/index.md
index a5acfc9945..9a50eb60fd 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -92,7 +92,7 @@ or as a development dependency for your project:
 $ npm install --save-dev mocha
 ```
 
-> To install Mocha v3.0.0 or newer with `npm`, you will need `npm` v2.14.2 or newer.  Additionally, to run Mocha, you will need Node.js v4 or newer.
+> Mocha currently requires Node.js v6.x or newer.
 
 Mocha can also be installed via [Bower](https://bower.io) (`bower install mocha`), and is available at [cdnjs](https://cdnjs.com/libraries/mocha).
 
diff --git a/package.json b/package.json
index 1c40ba5143..f8c014c7a8 100644
--- a/package.json
+++ b/package.json
@@ -449,7 +449,7 @@
     "_mocha": "./bin/_mocha"
   },
   "engines": {
-    "node": ">= 4.0.0"
+    "node": ">= 6.0.0"
   },
   "scripts": {
     "prepublishOnly": "nps test clean build",