diff --git a/.gitignore b/.gitignore
index bd5f5ee..735f4af 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,5 @@
 .DS_Store
 *.log
-.nyc_output/
 coverage/
 node_modules/
-is-hexadecimal.js
-is-hexadecimal.min.js
 yarn.lock
diff --git a/.prettierignore b/.prettierignore
index 6ef8749..cebe81f 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,5 +1,2 @@
 coverage/
-is-hexadecimal.js
-is-hexadecimal.min.js
-*.json
 *.md
diff --git a/index.js b/index.js
index 567c9d1..6c960a2 100644
--- a/index.js
+++ b/index.js
@@ -1,10 +1,6 @@
-'use strict'
-
-module.exports = hexadecimal
-
 // Check if the given character code, or the character code at the first
 // character, is hexadecimal.
-function hexadecimal(character) {
+export function isHexadecimal(character) {
   var code = typeof character === 'string' ? character.charCodeAt(0) : character
 
   return (
diff --git a/package.json b/package.json
index b857f0c..7eb758e 100644
--- a/package.json
+++ b/package.json
@@ -20,27 +20,25 @@
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
   ],
+  "sideEffects": false,
+  "type": "module",
+  "main": "index.js",
   "files": [
     "index.js"
   ],
   "devDependencies": {
-    "browserify": "^17.0.0",
-    "nyc": "^15.0.0",
+    "c8": "^7.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
     "tape": "^5.0.0",
-    "tinyify": "^3.0.0",
     "xo": "^0.38.0"
   },
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
-    "build-bundle": "browserify . -s isHexadecimal -o is-hexadecimal.js",
-    "build-mangle": "browserify . -s isHexadecimal -p tinyify -o is-hexadecimal.min.js",
-    "build": "npm run build-bundle && npm run build-mangle",
-    "test-api": "node test",
-    "test-coverage": "nyc --reporter lcov tape test.js",
-    "test": "npm run format && npm run build && npm run test-coverage"
+    "test-api": "node test.js",
+    "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test.js",
+    "test": "npm run format && npm run test-coverage"
   },
   "prettier": {
     "tabWidth": 2,
@@ -52,16 +50,10 @@
   },
   "xo": {
     "prettier": true,
-    "esnext": false,
-    "ignores": [
-      "is-hexadecimal.js"
-    ]
-  },
-  "nyc": {
-    "check-coverage": true,
-    "lines": 100,
-    "functions": 100,
-    "branches": 100
+    "rules": {
+      "no-var": "off",
+      "prefer-arrow-callback": "off"
+    }
   },
   "remarkConfig": {
     "plugins": [
diff --git a/readme.md b/readme.md
index c2b80bc..8c9929d 100644
--- a/readme.md
+++ b/readme.md
@@ -9,6 +9,9 @@ Check if a character is hexadecimal.
 
 ## Install
 
+This package is ESM only: Node 12+ is needed to use it and it must be `import`ed
+instead of `require`d.
+
 [npm][]:
 
 ```sh
@@ -18,20 +21,23 @@ npm install is-hexadecimal
 ## Use
 
 ```js
-var hexadecimal = require('is-hexadecimal')
+import {isHexadecimal} from 'is-hexadecimal'
 
-hexadecimal('a') // => true
-hexadecimal('0') // => true
-hexadecimal('G') // => false
-hexadecimal('💩') // => false
+isHexadecimal('a') // => true
+isHexadecimal('0') // => true
+isHexadecimal('G') // => false
+isHexadecimal('💩') // => false
 ```
 
 ## API
 
-### `hexadecimal(character|code)`
+This package exports the following identifiers: `isHexadecimal`.
+There is no default export.
+
+### `isHexadecimal(character|code)`
 
 Check whether the given character code (`number`), or the character code at the
-first position (`string`), is hexadecimal.
+first position (`string`), is isHexadecimal.
 
 ## Related
 
diff --git a/test.js b/test.js
index 316d473..ed076cd 100644
--- a/test.js
+++ b/test.js
@@ -1,22 +1,20 @@
-'use strict'
+import test from 'tape'
+import {isHexadecimal} from './index.js'
 
-var test = require('tape')
-var hexadecimal = require('.')
-
-test('hexadecimal(character)', function (t) {
-  t.ok(hexadecimal('a'))
-  t.ok(hexadecimal('F'))
-  t.ok(hexadecimal('0'))
-  t.ok(hexadecimal('a'.charCodeAt(0)))
-  t.notOk(hexadecimal('G'))
-  t.notOk(hexadecimal('a'.charCodeAt(0) - 1))
-  t.notOk(hexadecimal('f'.charCodeAt(0) + 1))
-  t.notOk(hexadecimal('A'.charCodeAt(0) - 1))
-  t.notOk(hexadecimal('F'.charCodeAt(0) + 1))
-  t.notOk(hexadecimal('0'.charCodeAt(0) - 1))
-  t.notOk(hexadecimal('9'.charCodeAt(0) + 1))
-  t.notOk(hexadecimal('g'.charCodeAt(0)))
-  t.notOk(hexadecimal('💩'))
+test('isHexadecimal(character)', function (t) {
+  t.ok(isHexadecimal('a'))
+  t.ok(isHexadecimal('F'))
+  t.ok(isHexadecimal('0'))
+  t.ok(isHexadecimal('a'.charCodeAt(0)))
+  t.notOk(isHexadecimal('G'))
+  t.notOk(isHexadecimal('a'.charCodeAt(0) - 1))
+  t.notOk(isHexadecimal('f'.charCodeAt(0) + 1))
+  t.notOk(isHexadecimal('A'.charCodeAt(0) - 1))
+  t.notOk(isHexadecimal('F'.charCodeAt(0) + 1))
+  t.notOk(isHexadecimal('0'.charCodeAt(0) - 1))
+  t.notOk(isHexadecimal('9'.charCodeAt(0) + 1))
+  t.notOk(isHexadecimal('g'.charCodeAt(0)))
+  t.notOk(isHexadecimal('💩'))
 
   t.end()
 })