diff --git a/.travis.yml b/.travis.yml
index 26df960..1611a3e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,18 +1,14 @@
 language: node_js
 
 node_js:
-  - stable
-  - v4
-  - v5
-  - v6
-  - v7
+  - 12
+  - 11
+  - 10
+  - 8
 
 sudo: false
 
-cache:
-  yarn: true
-  directories:
-    - node_modules
+cache: npm
 
 env:
   global:
diff --git a/index.js b/index.js
index b21f71e..5c78951 100644
--- a/index.js
+++ b/index.js
@@ -1,5 +1,3 @@
-'use strict'
-
 /**
  * Exports
  */
diff --git a/package.json b/package.json
index f90f73e..23439bb 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "date"
   ],
   "engines": {
-    "node": ">=4"
+    "node": ">=8"
   },
   "devDependencies": {
     "chai": "^4.2.0",
diff --git a/test.js b/test.js
index 7ae84f0..2080929 100644
--- a/test.js
+++ b/test.js
@@ -1,5 +1,3 @@
-'use strict'
-
 /* globals describe, it */
 
 const chai = require('chai')