diff --git a/README.md b/README.md
index 3fbf654..b6bc22b 100644
--- a/README.md
+++ b/README.md
@@ -150,6 +150,7 @@ Returns an object with the spec `{ value: string, unit: string, long: string }`.
 | [options.units] | <code>string</code> | Specify `'metric'`, `'iec'`, `'metric_octet'`, `'iec_octet'` or the name of a property from the custom units table in `options.customUnits`. Defaults to `metric`. |
 | [options.customUnits] | <code>object</code> | An object containing one or more custom unit lookup tables. |
 | [options.toStringFn] | <code>function</code> | A `toString` function to override the default. |
+| [options.locale] | <code>string</code> \| <code>Array.&lt;string&gt;</code> | The locale to use for number formatting (e.g. `'de-DE'`). Defaults to your system locale. Passed directed into [Intl.NumberFormat()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat). |
 
 <a name="module_byte-size--byteSize.defaultOptions"></a>
 
diff --git a/index.mjs b/index.mjs
index 86a17ea..bd219cd 100644
--- a/index.mjs
+++ b/index.mjs
@@ -104,6 +104,7 @@ class ByteSize {
  * @param [options.units] {string} - Specify `'metric'`, `'iec'`, `'metric_octet'`, `'iec_octet'` or the name of a property from the custom units table in `options.customUnits`. Defaults to `metric`.
  * @param [options.customUnits] {object} - An object containing one or more custom unit lookup tables.
  * @param [options.toStringFn] {function} - A `toString` function to override the default.
+ * @param [options.locale] {string|string[]} - The locale to use for number formatting (e.g. `'de-DE'`). Defaults to your system locale. Passed directed into [Intl.NumberFormat()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/NumberFormat).
  * @returns {object}
  * @alias module:byte-size
  */
diff --git a/jsdoc.conf b/jsdoc.conf
new file mode 100644
index 0000000..15d1b97
--- /dev/null
+++ b/jsdoc.conf
@@ -0,0 +1,5 @@
+{
+  "source": {
+    "includePattern": ".+\\.(js(doc|x)?|mjs)$"
+  }
+}
diff --git a/package.json b/package.json
index ba1265d..fc1714f 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "test": "npm run dist && npm run test:esm && npm run test:web",
     "test:esm": "test-runner --view.hide-skips test.mjs",
     "test:web": "web-runner test.mjs",
-    "docs": "jsdoc2md -t README.hbs dist/index.js > README.md",
+    "docs": "jsdoc2md -c jsdoc.conf -t README.hbs index.mjs > README.md",
     "cover": "c8 npm test && c8 report --reporter=text-lcov | coveralls",
     "dist": "rollup -c"
   },