diff --git a/_legacy.scss b/_legacy.scss
new file mode 100644
index 0000000..6935c81
--- /dev/null
+++ b/_legacy.scss
@@ -0,0 +1,56 @@
+@function hsv($h, $s, $v, $a: 1) {
+    // normalize h to degrees
+    $h: (0deg + $h) / 1deg;
+    $h: $h % 360;
+
+    // normalize s to fractions
+    @if (not unitless($s)) {
+        $s: $s / 100%;
+    }
+
+    // normalize v to fractions
+    @if (not unitless($v)) {
+        $v: $v / 100%;
+    }
+
+    // https://en.wikipedia.org/wiki/HSL_and_HSV#HSV_to_RGB
+    $c: $s * $v;
+    $h1: $h / 60;
+    $x: $c * (1 - abs($h1 % 2 - 1));
+
+    $r1: none; $g1: none; $b1: none;
+    @if ($h1 < 1) {
+        $r1: $c; $g1: $x; $b1: 0;
+    } @else if($h1 < 2) {
+        $r1: $x; $g1: $c; $b1: 0;
+    } @else if($h1 < 3) {
+        $r1: 0; $g1: $c; $b1: $x;
+    } @else if($h1 < 4) {
+        $r1: 0; $g1: $x; $b1: $c;
+    } @else if($h1 < 5) {
+        $r1: $x; $g1: 0; $b1: $c;
+    } @else {
+        $r1: $c; $g1: 0; $b1: $x;
+    }
+
+    $m: $v - $c;
+    $r: floor(($r1 + $m) * 255);
+    $g: floor(($g1 + $m) * 255);
+    $b: floor(($b1 + $m) * 255);
+
+    @return rgba($r, $g, $b, $a);
+}
+
+// some aliases
+
+@function hsva($h, $s, $v, $a) {
+    @return hsv($h, $s, $v, $a);
+}
+
+@function hsb($h, $s, $b, $a: 1) {
+    @return hsv($h, $s, $b, $a);
+}
+
+@function hsba($h, $s, $b, $a) {
+    @return hsv($h, $s, $b, $a);
+}
diff --git a/docs/index.rst b/docs/index.rst
index b082035..302af10 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -12,6 +12,11 @@ The helper tries to mimic ``hsl()`` syntax from css.
 
 The easiest way to import the helper is to use node-sass-package-importer_.
 
+Dart Sass
+---------
+
+Just import the module:
+
 .. code-block:: scss
 
     // node-sass-package-importer path syntax, adjust for your favorite importer
@@ -31,6 +36,21 @@ The easiest way to import the helper is to use node-sass-package-importer_.
         color: hsba(270, 50%, 100%, 1); // same as hsva()
     }
 
+libsass
+-------
+
+The package is designed for `sass` / Dart Sass with modules but it has support of `node-sass` / `libsass`.
+You need to import the legacy module explicitly:
+
+.. code-block::
+
+    // node-sass-package-importer path syntax, adjust for your favorite importer
+    @import "~sass-hsv/legacy"
+
+    a {
+        color: hsv(270, 50%, 100%); // #bf7fff
+    }
+
 License
 =======
 
diff --git a/package.json b/package.json
index c50b471..134e47d 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,11 @@
         "url": "https://sandfox.me/"
     },
     "sass": "_hsv.scss",
+    "scripts": {
+        "test": "mocha"
+    },
     "devDependencies": {
+        "chai": "^4.3.4",
         "mocha": "^9.1.1",
         "node-sass": "*",
         "sass": "*"
diff --git a/tests/spec/node-sass.js b/tests/spec/node-sass.js
new file mode 100644
index 0000000..fd7b490
--- /dev/null
+++ b/tests/spec/node-sass.js
@@ -0,0 +1,18 @@
+'use strict';
+
+const chai = require('chai');
+const assert = chai.assert;
+
+it('works with node-sass', function () {
+    const sass = require('node-sass');
+    const fs = require('fs');
+
+    const actual = sass.renderSync({
+        file: __dirname + '/sass/node-sass.scss',
+        outputStyle: 'compressed',
+    }).css;
+
+    const expected = fs.readFileSync(__dirname + '/sass/node-sass-result.css');
+
+    assert.equal(actual.toString(), expected.toString());
+});
diff --git a/tests/spec/sass/node-sass-result.css b/tests/spec/sass/node-sass-result.css
new file mode 100644
index 0000000..f23aa6f
--- /dev/null
+++ b/tests/spec/sass/node-sass-result.css
@@ -0,0 +1 @@
+a{color:#bf7fff}
diff --git a/tests/spec/sass/node-sass.scss b/tests/spec/sass/node-sass.scss
new file mode 100644
index 0000000..2ccf04a
--- /dev/null
+++ b/tests/spec/sass/node-sass.scss
@@ -0,0 +1,5 @@
+@import "hsv-legacy";
+
+a {
+    color: hsv(270, 50%, 100%);
+}