diff --git a/.eslintrc.js b/.eslintrc.js
index 0aa209f..83ac094 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -7,5 +7,8 @@ module.exports = {
   plugins: ["prettier"],
   rules: {
     "prettier/prettier": "error"
+  },
+  parserOptions: {
+    "ecmaVersion": 6
   }
 };
diff --git a/package.json b/package.json
index f1701fc..559804b 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,9 @@
 {
   "name": "base58",
   "version": "1.0.1",
-  "keywords": "base58, flickr",
+  "keywords": [
+    "base58, flickr"
+  ],
   "description": "Flickr Flavored Base58 Encoding and Decoding",
   "licenses": [
     {
@@ -22,14 +24,14 @@
   },
   "main": "./src/base58",
   "engines": {
-    "node": ">= 4"
+    "node": ">= 6"
   },
   "devDependencies": {
-    "eslint": "^4.1.1",
-    "eslint-config-prettier": "^2.3.0",
-    "eslint-plugin-prettier": "^2.2.0",
-    "mocha": "^3.4.2",
-    "prettier": "^1.5.3"
+    "eslint": "^5.6.0",
+    "eslint-config-prettier": "^3.0.0",
+    "eslint-plugin-prettier": "^2.7.0",
+    "mocha": "^5.2.0",
+    "prettier": "^1.14.3"
   },
   "scripts": {
     "lint": "eslint . --fix",
diff --git a/test/.eslintrc.js b/test/.eslintrc.js
index bf3479f..953b7b0 100644
--- a/test/.eslintrc.js
+++ b/test/.eslintrc.js
@@ -1,5 +1,8 @@
 module.exports = {
   env: {
     mocha: true
+  },
+  parserOptions: {
+    "ecmaVersion": 6
   }
 };