diff --git a/.travis.yml b/.travis.yml
index e155464..94ab01f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,5 +2,3 @@ language: node_js
 node_js:
   - '12'
   - '10'
-  - '8'
-  - '6'
diff --git a/index.d.ts b/index.d.ts
index 97f896e..a751feb 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,27 +1,20 @@
-declare const decamelize: {
-	/**
-	Convert a camelized string into a lowercased one with a custom separator: `unicornRainbow` → `unicorn_rainbow`.
+/**
+Convert a camelized string into a lowercased one with a custom separator: `unicornRainbow` → `unicorn_rainbow`.
 
-	@param string - The camelcase string to decamelize.
-	@param separator - The separator to use to put in between the words from `string`. Default: `'_'`.
+@param string - The camelcase string to decamelize.
+@param separator - The separator to use to put in between the words from `string`. Default: `'_'`.
 
-	@example
-	```
-	import decamelize = require('decamelize');
+@example
+```
+import decamelize = require('decamelize');
 
-	decamelize('unicornRainbow');
-	//=> 'unicorn_rainbow'
+decamelize('unicornRainbow');
+//=> 'unicorn_rainbow'
 
-	decamelize('unicornRainbow', '-');
-	//=> 'unicorn-rainbow'
-	```
-	*/
-	(string: string, separator?: string): string;
-
-	// TODO: Remove this for the next major release, refactor the whole definition to:
-	// declare function decamelize(string: string, separator?: string): string;
-	// export = decamelize;
-	default: typeof decamelize;
-};
+decamelize('unicornRainbow', '-');
+//=> 'unicorn-rainbow'
+```
+*/
+declare function decamelize(string: string, separator?: string): string;
 
 export = decamelize;
diff --git a/index.js b/index.js
index e383005..0861a6e 100644
--- a/index.js
+++ b/index.js
@@ -1,23 +1,12 @@
 'use strict';
-const xRegExp = require('xregexp');
 
-const decamelize = (text, separator = '_') => {
+module.exports = (text, separator = '_') => {
 	if (!(typeof text === 'string' && typeof separator === 'string')) {
 		throw new TypeError('The `text` and `separator` arguments should be of type `string`');
 	}
 
-	const regex1 = xRegExp('([\\p{Ll}\\d])(\\p{Lu})', 'g');
-	const regex2 = xRegExp('(\\p{Lu}+)(\\p{Lu}[\\p{Ll}\\d]+)', 'g');
-
 	return text
-		// TODO: Use this instead of `xregexp` when targeting Node.js 10:
-		// .replace(/([\p{Lowercase_Letter}\d])(\p{Uppercase_Letter})/gu, `$1${separator}$2`)
-		// .replace(/(\p{Lowercase_Letter}+)(\p{Uppercase_Letter}[\p{Lowercase_Letter}\d]+)/gu, `$1${separator}$2`)
-		.replace(regex1, `$1${separator}$2`)
-		.replace(regex2, `$1${separator}$2`)
+		.replace(/([\p{Lowercase_Letter}\d])(\p{Uppercase_Letter})/gu, `$1${separator}$2`)
+		.replace(/(\p{Uppercase_Letter}+)(\p{Uppercase_Letter}[\p{Lowercase_Letter}\d]+)/gu, `$1${separator}$2`)
 		.toLowerCase();
 };
-
-module.exports = decamelize;
-// TODO: Remove this for the next major release
-module.exports.default = decamelize;
diff --git a/package.json b/package.json
index b67d3e4..62fce4d 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
 		"url": "sindresorhus.com"
 	},
 	"engines": {
-		"node": ">=6"
+		"node": ">=10"
 	},
 	"scripts": {
 		"test": "xo && ava && tsd"
@@ -32,9 +32,6 @@
 		"text",
 		"convert"
 	],
-	"dependencies": {
-		"xregexp": "^4.2.4"
-	},
 	"devDependencies": {
 		"ava": "^1.4.1",
 		"tsd": "^0.7.2",