diff --git a/.eslintignore b/.eslintignore
index 4be6e16..c36bcaf 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1 +1,2 @@
-dist/*
\ No newline at end of file
+dist/*
+test/*
diff --git a/.eslintrc.json b/.eslintrc.json
index 1d1e020..9e547b2 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -6,7 +6,7 @@
   },
   "parserOptions": {
     "sourceType": "module",
-    "ecmaVersion": 2018
+    "ecmaVersion": 2020
   },
   "extends": "eslint:recommended",
   "rules": {
@@ -158,4 +158,4 @@
       "error"
     ]
   }
-}
\ No newline at end of file
+}
diff --git a/README.md b/README.md
index 2d42c3e..2bee426 100644
--- a/README.md
+++ b/README.md
@@ -17,23 +17,18 @@ npm install less-compile-roots
 Here is a basic programmatic usage example:
 
 ```javascript
-let lessCompileRoots = require("less-compile-roots");
+import {compileRoots} from "less-compile-roots";
 
-lessCompileRoots.compileRoots({
+let rootEntries = await compileRoots({
     // Glob pattern matching existing less files
     pattern: "src/**/*.less",
     // Pass any Less.js options you need
     lessOptions: {
         sourceMap: {sourceMapFileInline: true}
     }
-})
-.then(rootEntries => {
-    console.log("Compiled root files:");
-    console.log(rootEntries.join("\n"));
-})
-.catch(reason => {
-    console.error(reason);
 });
+console.log("Compiled root files:");
+console.log(rootEntries.join("\n"));
 ```
 
 If you prefer using the tool through the command line, please refer the [Command line usage](#command-line-usage) section.
@@ -50,7 +45,7 @@ The supported options are:
 
 * `pattern` _(required)_: a glob pattern (or a list of patterns) matching your source Less files. Please refer the [fast-glob docs](https://github.com/mrmlnc/fast-glob#patterns) for details;
 * `lessOptions` _(optional)_: the options object to pass to the [`less.render` method](http://lesscss.org/usage/#programmatic-usage). The [available options](http://lesscss.org/usage/#less-options) are listed in the official Less documentation;
-* `globOptions` _(optional)_: the options object to pass to the fast-glob function. See their [docs](https://github.com/mrmlnc/fast-glob#options-1) for details.
+* `globOptions` _(optional)_: the options object to pass to the fast-glob function. See their [docs](https://github.com/mrmlnc/fast-glob#options-3) for details.
 
 ### `getRoots(options)`
 
@@ -65,7 +60,7 @@ You may also use `less-compile-roots` through the command line interface:
 less-compile-roots --pattern=src/**/*.less
 
 # or use custom config from a specified file
-less-compile-roots --config=less-compile-config.js
+less-compile-roots --config=less-compile-config.cjs
 ```
 
 Available options:
@@ -78,6 +73,7 @@ Available options:
 Note that you cannot use the options `--pattern` and `--config` together. Specifying the `--pattern` option makes the module compile Less files using all default parameters. If you need to customize the parameters, create a config file and specify the path to it through the `--config` option (or just use the module [programmatically](#api) rather than in command line). Here is an example of such config file:
 
 ```javascript
+// less-compile-config.cjs
 let LessPlugin = require('less-plugin-myplugin');
 module.exports = {
     pattern: ["project-1/css/**/*.less", "project-2/css/**/*.less"],
@@ -93,7 +89,7 @@ In fact, the config module just exports an object which is then used as the `opt
 
 ## Requirements
 
-* NodeJS engine v9.11.2+
+* NodeJS engine v10.0.0+
 * Less pre-processor v2.0.0+
 
 ## Caveats
diff --git a/bin/less-compile-roots.js b/bin/less-compile-roots.cjs
similarity index 100%
rename from bin/less-compile-roots.js
rename to bin/less-compile-roots.cjs
diff --git a/dist/index.js b/dist/index.cjs
similarity index 73%
rename from dist/index.js
rename to dist/index.cjs
index 9bf5675..17ba500 100644
--- a/dist/index.js
+++ b/dist/index.cjs
@@ -2,13 +2,14 @@
 
 Object.defineProperty(exports, '__esModule', { value: true });
 
-let fs = require("fs");
-let util = require("util");
-let path = require("path");
-let fastGlob = require("fast-glob");
+var fs = require('fs');
+var path = require('path');
+var fastGlob = require('fast-glob');
+
+function _interopNamespaceDefaultOnly(e) {
+    return Object.freeze({__proto__: null, 'default': e});
+}
 
-let readFile = util.promisify(fs.readFile);
-let writeFile = util.promisify(fs.writeFile);
 let setExt = (path, ext, oldExtRE = /\.less$/) => path.replace(oldExtRE, "") + ext;
 
 let flat = Array.prototype.flat ? list => list.flat() : list => [].concat(...list);
@@ -17,7 +18,7 @@ async function getImports(entries) {
     let commentRE = /\/\*[\s\S]*?\*\/|\/\/\s*@import[^;]+;/g;
     let importRE = /(?<=@import\s[^"']*["']).+?(?=['"]\s*;)/g;
     let promises = entries.map(async entry => {
-        let data = await readFile(entry, "utf8");
+        let data = await fs.promises.readFile(entry, "utf8");
         data = data.replace(commentRE, "");
         let dir = path.dirname(entry);
         return (data.match(importRE) || []).map(importPath => {
@@ -32,20 +33,20 @@ async function getImports(entries) {
     return new Set(flat(importLists));
 }
 
-function compile(entries, lessOptions) {
-    let less = require("less");
+async function compile(entries, lessOptions) {
+    let less = (await Promise.resolve().then(function () { return /*#__PURE__*/_interopNamespaceDefaultOnly(require('less')); })).default;
     let inlineMap = lessOptions.sourceMap && lessOptions.sourceMap.sourceMapFileInline;
     let promises = entries.map(async entry => {
-        let data = await readFile(entry, "utf8");
+        let data = await fs.promises.readFile(entry, "utf8");
         let {css, map} = await less.render(data, {
             ...lessOptions,
             filename: entry
         });
-        let writeCSS = writeFile(setExt(entry, ".css"), css);
+        let writeCSS = fs.promises.writeFile(setExt(entry, ".css"), css);
         if (!map || inlineMap) {
             return writeCSS;
         }
-        let writeMap = writeFile(setExt(entry, ".css.map"), map);
+        let writeMap = fs.promises.writeFile(setExt(entry, ".css.map"), map);
         return Promise.all([writeCSS, writeMap]);
     });
     return Promise.all(promises);
diff --git a/package-lock.json b/package-lock.json
index 47dbfff..779ba04 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "less-compile-roots",
-  "version": "1.0.0",
+  "version": "2.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -939,9 +939,9 @@
       }
     },
     "rollup": {
-      "version": "2.45.1",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-2.45.1.tgz",
-      "integrity": "sha512-vPD+JoDj3CY8k6m1bLcAFttXMe78P4CMxoau0iLVS60+S9kLsv2379xaGy4NgYWu+h2WTlucpoLPAoUoixFBag==",
+      "version": "2.45.2",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-2.45.2.tgz",
+      "integrity": "sha512-kRRU7wXzFHUzBIv0GfoFFIN3m9oteY4uAsKllIpQDId5cfnkWF2J130l+27dzDju0E6MScKiV0ZM5Bw8m4blYQ==",
       "dev": true,
       "requires": {
         "fsevents": "~2.3.1"
diff --git a/package.json b/package.json
index 09bad20..edb164d 100644
--- a/package.json
+++ b/package.json
@@ -1,11 +1,16 @@
 {
   "name": "less-compile-roots",
-  "version": "1.0.0",
+  "version": "2.0.0",
   "description": "Tool for extracting and compiling root Less files",
-  "main": "dist/index.js",
-  "module": "src/index.mjs",
+  "type": "module",
+  "main": "./dist/index.cjs",
+  "module": "./src/index.mjs",
+  "exports": {
+    "import": "./src/index.mjs",
+    "require": "./dist/index.cjs"
+  },
   "bin": {
-    "less-compile-roots": "./bin/less-compile-roots.js"
+    "less-compile-roots": "./bin/less-compile-roots.cjs"
   },
   "files": [
     "bin",
@@ -35,12 +40,12 @@
   },
   "devDependencies": {
     "eslint": "^7.24.0",
-    "rollup": "^2.45.1"
+    "rollup": "^2.45.2"
   },
   "peerDependencies": {
     "less": ">=2.0.0"
   },
   "engines": {
-    "node": ">=9.11.2"
+    "node": ">=10.0.0"
   }
 }
diff --git a/rollup.config.js b/rollup.config.js
index f765258..65afadd 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -1,7 +1,9 @@
 export default {
     input: "src/index.mjs",
     output: {
-        file: "dist/index.js",
-        format: "cjs"
-    }
+        file: "dist/index.cjs",
+        format: "cjs",
+        interop: id => id === "less" ? "defaultOnly" : "default"
+    },
+    external: () => true
 };
diff --git a/src/index.mjs b/src/index.mjs
index d6211e4..3bf27f8 100644
--- a/src/index.mjs
+++ b/src/index.mjs
@@ -1,10 +1,7 @@
-let fs = require("fs");
-let util = require("util");
-let path = require("path");
-let fastGlob = require("fast-glob");
+import {promises as fsPromises} from "fs";
+import path from "path";
+import fastGlob from "fast-glob";
 
-let readFile = util.promisify(fs.readFile);
-let writeFile = util.promisify(fs.writeFile);
 let setExt = (path, ext, oldExtRE = /\.less$/) => path.replace(oldExtRE, "") + ext;
 
 let flat = Array.prototype.flat ? list => list.flat() : list => [].concat(...list);
@@ -13,7 +10,7 @@ async function getImports(entries) {
     let commentRE = /\/\*[\s\S]*?\*\/|\/\/\s*@import[^;]+;/g;
     let importRE = /(?<=@import\s[^"']*["']).+?(?=['"]\s*;)/g;
     let promises = entries.map(async entry => {
-        let data = await readFile(entry, "utf8");
+        let data = await fsPromises.readFile(entry, "utf8");
         data = data.replace(commentRE, "");
         let dir = path.dirname(entry);
         return (data.match(importRE) || []).map(importPath => {
@@ -28,20 +25,20 @@ async function getImports(entries) {
     return new Set(flat(importLists));
 }
 
-function compile(entries, lessOptions) {
-    let less = require("less");
+async function compile(entries, lessOptions) {
+    let less = (await import("less")).default;
     let inlineMap = lessOptions.sourceMap && lessOptions.sourceMap.sourceMapFileInline;
     let promises = entries.map(async entry => {
-        let data = await readFile(entry, "utf8");
+        let data = await fsPromises.readFile(entry, "utf8");
         let {css, map} = await less.render(data, {
             ...lessOptions,
             filename: entry
         });
-        let writeCSS = writeFile(setExt(entry, ".css"), css);
+        let writeCSS = fsPromises.writeFile(setExt(entry, ".css"), css);
         if (!map || inlineMap) {
             return writeCSS;
         }
-        let writeMap = writeFile(setExt(entry, ".css.map"), map);
+        let writeMap = fsPromises.writeFile(setExt(entry, ".css.map"), map);
         return Promise.all([writeCSS, writeMap]);
     });
     return Promise.all(promises);
diff --git a/test/.gitignore b/test/.gitignore
deleted file mode 100644
index 2318862..0000000
--- a/test/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-*.css
\ No newline at end of file
diff --git a/test/less-compile-config.cjs b/test/less-compile-config.cjs
new file mode 100644
index 0000000..06ba324
--- /dev/null
+++ b/test/less-compile-config.cjs
@@ -0,0 +1,6 @@
+module.exports = {
+    pattern: "less/*.less",
+    lessOptions: {
+        sourceMap: {}
+    }
+};
diff --git a/test/less/root-01.css b/test/less/root-01.css
new file mode 100644
index 0000000..e48e92b
--- /dev/null
+++ b/test/less/root-01.css
@@ -0,0 +1,12 @@
+body {
+  background: #000;
+}
+/*
+a {
+    color:#0a0;
+}
+@import "root-04";
+some text
+*/
+/*@import "root-05";*/
+/* child-01 */
diff --git a/test/less/root-01.css.map b/test/less/root-01.css.map
new file mode 100644
index 0000000..edad92d
--- /dev/null
+++ b/test/less/root-01.css.map
@@ -0,0 +1 @@
+{"version":3,"sources":["less/root-01.less"],"names":[],"mappings":"AAAA;EACI,gBAAA"}
\ No newline at end of file
diff --git a/test/less/root-02.css b/test/less/root-02.css
new file mode 100644
index 0000000..d12b1b4
--- /dev/null
+++ b/test/less/root-02.css
@@ -0,0 +1,6 @@
+/* child-02 */
+/* child-02-1 */
+/* child-02-2 */
+body {
+  background: #000;
+}
diff --git a/test/less/root-02.css.map b/test/less/root-02.css.map
new file mode 100644
index 0000000..7c049fc
--- /dev/null
+++ b/test/less/root-02.css.map
@@ -0,0 +1 @@
+{"version":3,"sources":["less/root-02.less"],"names":[],"mappings":";;;AAGA;EACI,gBAAA"}
\ No newline at end of file
diff --git a/test/less/root-03.css b/test/less/root-03.css
new file mode 100644
index 0000000..3e19b69
--- /dev/null
+++ b/test/less/root-03.css
@@ -0,0 +1,4 @@
+body {
+  background: #000;
+}
+/* child-03 */
diff --git a/test/less/root-03.css.map b/test/less/root-03.css.map
new file mode 100644
index 0000000..e3dd040
--- /dev/null
+++ b/test/less/root-03.css.map
@@ -0,0 +1 @@
+{"version":3,"sources":["less/root-03.less"],"names":[],"mappings":"AAAA;EACI,gBAAA"}
\ No newline at end of file
diff --git a/test/less/root-04.css b/test/less/root-04.css
new file mode 100644
index 0000000..78c0719
--- /dev/null
+++ b/test/less/root-04.css
@@ -0,0 +1,5 @@
+/* child-04 */
+/* child-04-1 */
+body {
+  background: #000;
+}
diff --git a/test/less/root-04.css.map b/test/less/root-04.css.map
new file mode 100644
index 0000000..55a042a
--- /dev/null
+++ b/test/less/root-04.css.map
@@ -0,0 +1 @@
+{"version":3,"sources":["less/root-04.less"],"names":[],"mappings":";;AAiBA;EACI,gBAAA"}
\ No newline at end of file
diff --git a/test/less/root-05.css b/test/less/root-05.css
new file mode 100644
index 0000000..c6af4d8
--- /dev/null
+++ b/test/less/root-05.css
@@ -0,0 +1,4 @@
+/* child-05-1 */
+body {
+  background: #000;
+}
diff --git a/test/less/root-05.css.map b/test/less/root-05.css.map
new file mode 100644
index 0000000..a208e72
--- /dev/null
+++ b/test/less/root-05.css.map
@@ -0,0 +1 @@
+{"version":3,"sources":["less/root-05.less"],"names":[],"mappings":";AAKA;EACI,gBAAA"}
\ No newline at end of file
diff --git a/test/package-lock.json b/test/package-lock.json
index 6d4650f..603ad9c 100644
--- a/test/package-lock.json
+++ b/test/package-lock.json
@@ -176,6 +176,23 @@
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
       "integrity": "sha1-2Klr13/Wjfd5OnMDajug1UBdR3s="
     },
+    "copy-anything": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/copy-anything/-/copy-anything-2.0.3.tgz",
+      "integrity": "sha512-GK6QUtisv4fNS+XcI7shX0Gx9ORg7QqIznyfho79JTnX1XhLiyZHfftvGiziqzRiEi/Bjhgpi+D2o7HxJFPnDQ==",
+      "requires": {
+        "is-what": "^3.12.0"
+      }
+    },
+    "debug": {
+      "version": "3.2.7",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-3.2.7.tgz",
+      "integrity": "sha512-CFjzYYAi4ThfiQvizrFQevTTXHtnCqWfe7x1AhgEscTz6ZbLbfoLRLPugTQyBth6f8ZERVUSyWHFD/7Wu4t1XQ==",
+      "optional": true,
+      "requires": {
+        "ms": "^2.1.1"
+      }
+    },
     "decamelize": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/decamelize/-/decamelize-1.2.0.tgz",
@@ -230,9 +247,9 @@
       }
     },
     "errno": {
-      "version": "0.1.7",
-      "resolved": "https://registry.npmjs.org/errno/-/errno-0.1.7.tgz",
-      "integrity": "sha512-MfrRBDWzIWifgq6tJj60gkAwtLNb6sQPlcFrSOflcP1aFmmruKQ2wRnze/8V6kgyz7H3FF8Npzv78mZ7XLLflg==",
+      "version": "0.1.8",
+      "resolved": "https://registry.npmjs.org/errno/-/errno-0.1.8.tgz",
+      "integrity": "sha512-dJ6oBr5SQ1VSd9qkk7ByRgb/1SH4JZjCHSW/mr63/QcXO9zLVxvJ6Oy13nio03rxpSnVDDjFor75SjVeZWPW/A==",
       "optional": true,
       "requires": {
         "prr": "~1.0.1"
@@ -357,6 +374,15 @@
       "resolved": "https://registry.npmjs.org/hosted-git-info/-/hosted-git-info-2.8.8.tgz",
       "integrity": "sha512-f/wzC2QaWBs7t9IYqB4T3sR1xviIViXJRJTWBlx2Gf3g0Xi5vI7Yy4koXQ1c9OYDGHN9sBy1DQ2AB8fqZBWhUg=="
     },
+    "iconv-lite": {
+      "version": "0.4.24",
+      "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.24.tgz",
+      "integrity": "sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==",
+      "optional": true,
+      "requires": {
+        "safer-buffer": ">= 2.1.2 < 3"
+      }
+    },
     "ignore": {
       "version": "5.1.8",
       "resolved": "https://registry.npmjs.org/ignore/-/ignore-5.1.8.tgz",
@@ -425,6 +451,11 @@
       "resolved": "https://registry.npmjs.org/is-plain-obj/-/is-plain-obj-1.1.0.tgz",
       "integrity": "sha1-caUMhCnfync8kqOQpKA7OfzVHT4="
     },
+    "is-what": {
+      "version": "3.14.1",
+      "resolved": "https://registry.npmjs.org/is-what/-/is-what-3.14.1.tgz",
+      "integrity": "sha512-sNxgpk9793nzSs7bA6JQJGeIuRBQhAaNGG77kzYQgMkrID+lS6SlK07K5LaptscDlSaIgH+GPFzf+d75FVxozA=="
+    },
     "js-tokens": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
@@ -441,31 +472,33 @@
       "integrity": "sha512-dcS1ul+9tmeD95T+x28/ehLgd9mENa3LsvDTtzm3vyBEO7RPptvAD+t44WVXaUjTBRcrpFeFlC8WCruUR456hw=="
     },
     "less": {
-      "version": "3.12.2",
-      "resolved": "https://registry.npmjs.org/less/-/less-3.12.2.tgz",
-      "integrity": "sha512-+1V2PCMFkL+OIj2/HrtrvZw0BC0sYLMICJfbQjuj/K8CEnlrFX6R5cKKgzzttsZDHyxQNL1jqMREjKN3ja/E3Q==",
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/less/-/less-4.1.1.tgz",
+      "integrity": "sha512-w09o8tZFPThBscl5d0Ggp3RcrKIouBoQscnOMgFH3n5V3kN/CXGHNfCkRPtxJk6nKryDXaV9aHLK55RXuH4sAw==",
       "requires": {
+        "copy-anything": "^2.0.1",
         "errno": "^0.1.1",
         "graceful-fs": "^4.1.2",
         "image-size": "~0.5.0",
         "make-dir": "^2.1.0",
         "mime": "^1.4.1",
-        "native-request": "^1.0.5",
+        "needle": "^2.5.2",
+        "parse-node-version": "^1.0.1",
         "source-map": "~0.6.0",
         "tslib": "^1.10.0"
       }
     },
     "less-compile-roots": {
-      "version": "file:../less-compile-roots-1.0.0.tgz",
-      "integrity": "sha512-lGBw2tYHY0LfUfr9nlUc7IsptYqQ9CsP1mfl2v5bl9P1NPTMLYZxFo4onG52fxczVZF7tKoydwuX/EMA2N8nLw==",
+      "version": "file:../less-compile-roots-2.0.0.tgz",
+      "integrity": "sha512-MXwRT6FymcfnKPHzcM37VNGeQsHoZOrLG1mSSNHv2Fh7mWp4BHc4gx8xFvGWHIfkkpxrDY+ZWmhCuPQT6z31jw==",
       "requires": {
-        "fast-glob": "^3.2.2"
+        "fast-glob": "^3.2.5"
       },
       "dependencies": {
         "fast-glob": {
-          "version": "3.2.2",
-          "resolved": "https://registry.npmjs.org/fast-glob/-/fast-glob-3.2.2.tgz",
-          "integrity": "sha512-UDV82o4uQyljznxwMxyVRJgZZt3O5wENYojjzbaGEGZgeOxkLFf+V4cnUD+krzb2F72E18RhamkMZ7AdeggF7A==",
+          "version": "3.2.5",
+          "resolved": "https://registry.npmjs.org/fast-glob/-/fast-glob-3.2.5.tgz",
+          "integrity": "sha512-2DtFcgT68wiTTiwZ2hNdJfcHNke9XOfnwmBRWXhmeKM8rF0TGwmC/Qto3S7RoZKp5cilZbxzO5iTNTQsJ+EeDg==",
           "requires": {
             "@nodelib/fs.stat": "^2.0.2",
             "@nodelib/fs.walk": "^1.2.3",
@@ -476,9 +509,9 @@
           }
         },
         "picomatch": {
-          "version": "2.2.1",
-          "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.2.1.tgz",
-          "integrity": "sha512-ISBaA8xQNmwELC7eOjqFKMESB2VIqt4PPDD0nsS95b/9dZXvVKOlz9keMSnoGGKcOHXfTvDD6WMaRoSc9UuhRA=="
+          "version": "2.2.3",
+          "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.2.3.tgz",
+          "integrity": "sha512-KpELjfwcCDUb9PeigTs2mBJzXUPzAuP2oPcA989He8Rte0+YUAjw1JVedDhuTKPkHjSYzMN3npC9luThGYEKdg=="
         }
       }
     },
@@ -571,12 +604,23 @@
         "kind-of": "^6.0.3"
       }
     },
-    "native-request": {
-      "version": "1.0.7",
-      "resolved": "https://registry.npmjs.org/native-request/-/native-request-1.0.7.tgz",
-      "integrity": "sha512-9nRjinI9bmz+S7dgNtf4A70+/vPhnd+2krGpy4SUlADuOuSa24IDkNaZ+R/QT1wQ6S8jBdi6wE7fLekFZNfUpQ==",
+    "ms": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
+      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
       "optional": true
     },
+    "needle": {
+      "version": "2.6.0",
+      "resolved": "https://registry.npmjs.org/needle/-/needle-2.6.0.tgz",
+      "integrity": "sha512-KKYdza4heMsEfSWD7VPUIz3zX2XDwOyX2d+geb4vrERZMT5RMU6ujjaD+I5Yr54uZxQ2w6XRTAhHBbSCyovZBg==",
+      "optional": true,
+      "requires": {
+        "debug": "^3.2.6",
+        "iconv-lite": "^0.4.4",
+        "sax": "^1.2.4"
+      }
+    },
     "normalize-package-data": {
       "version": "2.5.0",
       "resolved": "https://registry.npmjs.org/normalize-package-data/-/normalize-package-data-2.5.0.tgz",
@@ -636,6 +680,11 @@
         "lines-and-columns": "^1.1.6"
       }
     },
+    "parse-node-version": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/parse-node-version/-/parse-node-version-1.0.1.tgz",
+      "integrity": "sha512-3YHlOa/JgH6Mnpr05jP9eDG254US9ek25LyIxZlDItp2iJtwyaXQb57lBYLdT3MowkUFYEV2XXNAYIPlESvJlA=="
+    },
     "path-exists": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz",
@@ -748,6 +797,18 @@
       "resolved": "https://registry.npmjs.org/run-parallel/-/run-parallel-1.1.9.tgz",
       "integrity": "sha512-DEqnSRTDw/Tc3FXf49zedI638Z9onwUotBMiUFKmrO2sdFKIbXamXGQ3Axd4qgphxKB4kw/qP1w5kTxnfU1B9Q=="
     },
+    "safer-buffer": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
+      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==",
+      "optional": true
+    },
+    "sax": {
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/sax/-/sax-1.2.4.tgz",
+      "integrity": "sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw==",
+      "optional": true
+    },
     "semver": {
       "version": "5.7.1",
       "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
@@ -822,9 +883,9 @@
       "integrity": "sha512-C4+gOpvmxaSMKuEf9Qc134F1ZuOHVXKRbtEflf4NTtuuJDEIJ9p5PXsalL8SkeRw+qit1Mo+yuvMPAKwWg/1hA=="
     },
     "tslib": {
-      "version": "1.13.0",
-      "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.13.0.tgz",
-      "integrity": "sha512-i/6DQjL8Xf3be4K/E6Wgpekn5Qasl1usyw++dAA35Ue5orEn65VIxOA+YvNNl9HV3qv70T7CNwjODHZrLwvd1Q=="
+      "version": "1.14.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.14.1.tgz",
+      "integrity": "sha512-Xni35NKzjgMrwevysHTCArtLDpPvye8zV/0E4EyYn43P7/7qvQwPh9BGkHewbMulVntbigmcT7rdX3BNo9wRJg=="
     },
     "type-fest": {
       "version": "0.13.1",
diff --git a/test/package.json b/test/package.json
index ed8801a..75bb8fd 100644
--- a/test/package.json
+++ b/test/package.json
@@ -2,16 +2,22 @@
   "name": "less-compile-root-test",
   "version": "1.0.0",
   "description": "Simple test package for the less-compile-roots module",
-  "main": "index.js",
+  "private": true,
+  "type": "module",
+  "main": "./test-api.cjs",
+  "exports": "./test-api.mjs",
   "scripts": {
-    "test": "del 'less/*.css' && less-compile-roots --pattern=less/*.less",
-    "test-api": "del 'less/*.css' && node ./test-api.js"
+    "cleanup": "del 'less/*.css' 'less/*.css.map'",
+    "test-cli": "npm run cleanup && less-compile-roots --pattern=less/*.less",
+    "test-cli-config": "npm run cleanup && less-compile-roots --config=less-compile-config.cjs",
+    "test-api-mjs": "npm run cleanup && node ./test-api.mjs",
+    "test-api-cjs": "npm run cleanup && node ./test-api.cjs"
   },
   "author": "Amphiluke",
   "license": "MIT",
   "dependencies": {
     "del-cli": "^3.0.1",
-    "less": "^3.12.2",
-    "less-compile-roots": "file:../less-compile-roots-1.0.0.tgz"
+    "less": "^4.1.1",
+    "less-compile-roots": "file:../less-compile-roots-2.0.0.tgz"
   }
 }
diff --git a/test/test-api.js b/test/test-api.cjs
similarity index 69%
rename from test/test-api.js
rename to test/test-api.cjs
index 0f9511c..b3ece3e 100644
--- a/test/test-api.js
+++ b/test/test-api.cjs
@@ -1,6 +1,6 @@
-let lessCompileRoots = require("less-compile-roots");
+let {compileRoots} = require("less-compile-roots");
 
-lessCompileRoots.compileRoots({
+compileRoots({
     pattern: "less/**/*.less"
 })
 .then(rootEntries => {
diff --git a/test/test-api.mjs b/test/test-api.mjs
new file mode 100644
index 0000000..d6284d1
--- /dev/null
+++ b/test/test-api.mjs
@@ -0,0 +1,7 @@
+import {compileRoots} from "less-compile-roots";
+
+let rootEntries = await compileRoots({
+    pattern: "less/**/*.less"
+});
+console.info("Compiled root files:");
+console.info(rootEntries.join("\n"));