diff --git a/README.md b/README.md
index a0316a076..e61dd27dd 100644
--- a/README.md
+++ b/README.md
@@ -193,7 +193,7 @@ Options
 | flavor | `"normal" \| "sdk"` | `"normal"` | Runtime flavor |
 | platform | `"linux" \| "osx" \| "win"` | | Host platform |
 | arch | `"ia32" \| "x64" \| "arm64"` | | Host architecture |
-| downloadUrl | `"https://dl.nwjs.io" \| "https://npm.taobao.org/mirrors/nwjs" \| https://npmmirror.com/mirrors/nwjs \| "https://github.com/corwin-of-amber/nw.js/releases/"` | `"https://dl.nwjs.io"` | Download server |
+| downloadUrl | `"https://dl.nwjs.io" \| "https://npm.taobao.org/mirrors/nwjs" \| https://npmmirror.com/mirrors/nwjs \| "https://github.com/corwin-of-amber/nw.js/releases/"` | `"https://dl.nwjs.io"` | Download server. Supports file systems too (for example `file:///home/localghost/nwjs_mirror`) |
 | manifestUrl | `"https://nwjs.io/versions" \| "https://raw.githubusercontent.com/nwutils/nw-builder/main/src/util/osx.arm.versions.json"` | `"https://nwjs.io/versions"` | Versions manifest |
 | cacheDir | `string` | `"./cache"` | Directory to cache NW binaries |
 | srcDir | `string` | `"./"` | File paths to application code |
diff --git a/src/get/index.js b/src/get/index.js
index a4638002c..30bfbaafb 100644
--- a/src/get/index.js
+++ b/src/get/index.js
@@ -33,6 +33,13 @@ import util from "../util.js";
  */
 async function get(options) {
 
+  const uri = new url.URL(options.downloadUrl);
+
+  /* Download server is the cached directory. */
+  if (uri.protocol === 'file:') {
+    options.cacheDir = path.resolve(decodeURIComponent(options.downloadUrl.slice('file://'.length)));
+  }
+
   /**
    * If `options.cacheDir` exists, then `true`. Otherwise, it is `false`.
    *