diff --git a/package.json b/package.json
index c5b177cb1..b6465b292 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
     "@grpc/grpc-js": "~1.8.0",
     "@grpc/proto-loader": "^0.7.0",
     "@types/long": "^4.0.0",
+    "@types/rimraf": "^3.0.2",
     "abort-controller": "^3.0.0",
     "duplexify": "^4.0.0",
     "fast-text-encoding": "^1.0.3",
@@ -32,7 +33,7 @@
   },
   "devDependencies": {
     "@compodoc/compodoc": "1.1.19",
-    "@types/fs-extra": "^9.0.0",
+    "@types/mkdirp": "^1.0.2",
     "@types/mocha": "^9.0.0",
     "@types/ncp": "^2.0.1",
     "@types/node": "^18.0.0",
@@ -40,13 +41,11 @@
     "@types/object-hash": "^3.0.0",
     "@types/proxyquire": "^1.3.28",
     "@types/pumpify": "^1.4.1",
-    "@types/rimraf": "^3.0.0",
     "@types/sinon": "^10.0.0",
     "@types/uglify-js": "^3.17.0",
     "c8": "^7.0.0",
     "codecov": "^3.1.0",
     "execa": "^5.0.0",
-    "fs-extra": "^10.0.0",
     "google-proto-files": "^3.0.0",
     "gts": "^3.1.0",
     "linkinator": "^4.0.0",
diff --git a/test/system-test/test.clientlibs.ts b/test/system-test/test.clientlibs.ts
index b050115a6..efe822b80 100644
--- a/test/system-test/test.clientlibs.ts
+++ b/test/system-test/test.clientlibs.ts
@@ -21,8 +21,8 @@ import * as rimraf from 'rimraf';
 import * as util from 'util';
 import {describe, it, before} from 'mocha';
 
-const mkdir = util.promisify(fs.mkdir);
 const rmrf = util.promisify(rimraf);
+const mkdir = util.promisify(fs.mkdir);
 const readFile = util.promisify(fs.readFile);
 const writeFile = util.promisify(fs.writeFile);
 
diff --git a/test/unit/minify.ts b/test/unit/minify.ts
index eea8e0b9a..80ae14df3 100644
--- a/test/unit/minify.ts
+++ b/test/unit/minify.ts
@@ -18,10 +18,10 @@ import * as fs from 'fs';
 import {promises as fsp} from 'fs';
 import * as rimraf from 'rimraf';
 import * as path from 'path';
-import * as util from 'util';
 import * as minify from '../../tools/minify';
+import {promisify} from 'util';
 
-const rmrf = util.promisify(rimraf);
+const rmrf = promisify(rimraf);
 const testDir = path.join(process.cwd(), '.minify-test');
 const fixturesDir = path.join(__dirname, '..', 'fixtures');
 
diff --git a/tools/prepublish.ts b/tools/prepublish.ts
index b7a91b113..b4b350609 100644
--- a/tools/prepublish.ts
+++ b/tools/prepublish.ts
@@ -14,9 +14,17 @@
  * limitations under the License.
  */
 
-import * as fs from 'fs-extra';
 import {getProtoPath} from 'google-proto-files';
 import * as path from 'path';
+// Note: the following three imports will be all gone when we support Node.js 16+.
+// But until then, we'll use these modules.
+import * as rimraf from 'rimraf';
+import * as mkdirp from 'mkdirp';
+import * as ncp from 'ncp';
+import {promisify} from 'util';
+
+const ncpp = promisify(ncp);
+const rmrf = promisify(rimraf);
 
 const subdirs = [
   'api',
@@ -31,14 +39,17 @@ const subdirs = [
 ];
 
 async function main() {
-  await fs.remove(path.join('protos', 'google'));
-  await fs.ensureDir(path.join('protos', 'google'));
+  await rmrf(path.join('protos', 'google'));
+  await mkdirp(path.join('protos', 'google'));
 
-  subdirs.forEach(async subdir => {
+  for (const subdir of subdirs) {
     const src = getProtoPath(subdir);
     const target = path.join('protos', 'google', subdir);
-    await fs.copy(src, target);
-  });
+    console.log(`Copying protos from ${src} to ${target}`);
+    await mkdirp(target);
+    await ncpp(src, target);
+  }
+  console.log('Protos have been copied successfully');
 }
 
 main().catch(console.error);