diff --git a/extra/download-dist.js b/extra/download-dist.js
index dc64166c..c184c284 100644
--- a/extra/download-dist.js
+++ b/extra/download-dist.js
@@ -4,6 +4,7 @@ const tar = require("tar");
 
 const packageJSON = require("../package.json");
 const fs = require("fs");
+const rmSync = require("./fs-rmSync.js");
 const version = packageJSON.version;
 
 const filename = "dist.tar.gz";
@@ -21,7 +22,7 @@ function download(url) {
             if (fs.existsSync("./dist")) {
 
                 if (fs.existsSync("./dist-backup")) {
-                    fs.rmdirSync("./dist-backup", {
+                    rmSync("./dist-backup", {
                         recursive: true
                     });
                 }
@@ -35,7 +36,7 @@ function download(url) {
 
             tarStream.on("close", () => {
                 if (fs.existsSync("./dist-backup")) {
-                    fs.rmdirSync("./dist-backup", {
+                    rmSync("./dist-backup", {
                         recursive: true
                     });
                 }
diff --git a/extra/fs-rmSync.js b/extra/fs-rmSync.js
new file mode 100644
index 00000000..8def68d0
--- /dev/null
+++ b/extra/fs-rmSync.js
@@ -0,0 +1,20 @@
+const fs = require("fs");
+/**
+ * Detect if `fs.rmSync` is available
+ * to avoid the runtime warning triggered for using `fs.rmdirSync` with `{ recursive: true }` in Node.js v16,
+ * or the `recursive` property removing completely in the future Node.js version.
+ * See the link below.
+ * @link https://nodejs.org/docs/latest-v16.x/api/deprecations.html#dep0147-fsrmdirpath--recursive-true-
+ * @param {fs.PathLike} path Valid types for path values in "fs".
+ * @param {fs.RmDirOptions} [options] options for `fs.rmdirSync`, if `fs.rmSync` is available and property `recursive` is true, it will automatically have property `force` with value `true`.
+ */
+const rmSync = (path, options) => {
+    if (typeof fs.rmSync === "function") {
+        if (options.recursive) {
+            options.force = true;
+        }
+        return fs.rmSync(path, options);
+    }
+    return fs.rmdirSync(path, options);
+};
+module.exports = rmSync;
diff --git a/extra/update-language-files/index.js b/extra/update-language-files/index.js
index 7ba30cc0..1f58d01f 100644
--- a/extra/update-language-files/index.js
+++ b/extra/update-language-files/index.js
@@ -3,6 +3,7 @@
 import fs from "fs";
 import path from "path";
 import util from "util";
+import rmSync from "../fs-rmSync.js";
 
 // https://stackoverflow.com/questions/13786160/copy-folder-recursively-in-node-js
 /**
@@ -30,7 +31,7 @@ console.log("Arguments:", process.argv);
 const baseLangCode = process.argv[2] || "en";
 console.log("Base Lang: " + baseLangCode);
 if (fs.existsSync("./languages")) {
-    fs.rmdirSync("./languages", { recursive: true });
+    rmSync("./languages", { recursive: true });
 }
 copyRecursiveSync("../../src/languages", "./languages");
 
@@ -61,7 +62,7 @@ for (const file of files) {
 
     // En first
     for (const key in en) {
-        if (! obj[key]) {
+        if (!obj[key]) {
             obj[key] = en[key];
         }
     }
@@ -69,7 +70,7 @@ for (const file of files) {
     if (baseLang !== en) {
         // Base second
         for (const key in baseLang) {
-            if (! obj[key]) {
+            if (!obj[key]) {
                 obj[key] = key;
             }
         }
@@ -82,5 +83,5 @@ for (const file of files) {
     fs.writeFileSync(`../../src/languages/${file}`, code);
 }
 
-fs.rmdirSync("./languages", { recursive: true });
+rmSync("./languages", { recursive: true });
 console.log("Done. Fixing formatting by ESLint...");
diff --git a/extra/update-version.js b/extra/update-version.js
index 2e3b42da..499426b8 100644
--- a/extra/update-version.js
+++ b/extra/update-version.js
@@ -1,5 +1,6 @@
 const pkg = require("../package.json");
 const fs = require("fs");
+const rmSync = require("./fs-rmSync.js");
 const child_process = require("child_process");
 const util = require("../src/util");
 
@@ -11,14 +12,14 @@ const newVersion = process.argv[2];
 console.log("Old Version: " + oldVersion);
 console.log("New Version: " + newVersion);
 
-if (! newVersion) {
+if (!newVersion) {
     console.error("invalid version");
     process.exit(1);
 }
 
 const exists = tagExists(newVersion);
 
-if (! exists) {
+if (!exists) {
 
     // Process package.json
     pkg.version = newVersion;
@@ -55,7 +56,7 @@ function tag(version) {
 }
 
 function tagExists(version) {
-    if (! version) {
+    if (!version) {
         throw new Error("invalid version");
     }
 
@@ -93,7 +94,7 @@ function updateWiki(oldVersion, newVersion) {
 
 function safeDelete(dir) {
     if (fs.existsSync(dir)) {
-        fs.rmdirSync(dir, {
+        rmSync(dir, {
             recursive: true,
         });
     }
diff --git a/test/prepare-jest.js b/test/prepare-jest.js
index 9dfaba7d..3fd89d10 100644
--- a/test/prepare-jest.js
+++ b/test/prepare-jest.js
@@ -1,9 +1,10 @@
 const fs = require("fs");
+const rmSync = require("../extra/fs-rmSync.js");
 
 const path = "./data/test-chrome-profile";
 
 if (fs.existsSync(path)) {
-    fs.rmdirSync(path, {
+    rmSync(path, {
         recursive: true,
     });
 }
diff --git a/test/prepare-test-server.js b/test/prepare-test-server.js
index 0e49c7fb..1a9b04df 100644
--- a/test/prepare-test-server.js
+++ b/test/prepare-test-server.js
@@ -1,9 +1,10 @@
 const fs = require("fs");
+const rmSync = require("../extra/fs-rmSync.js");
 
 const path = "./data/test";
 
 if (fs.existsSync(path)) {
-    fs.rmdirSync(path, {
+    rmSync(path, {
         recursive: true,
     });
 }