diff --git a/lib/util/fs/index.ts b/lib/util/fs/index.ts
index 71f4c42bf3bc6c8479f51c1c8b152c31cb732ab9..be10caffd13b3462012409be1ca0d84f0a73bf80 100644
--- a/lib/util/fs/index.ts
+++ b/lib/util/fs/index.ts
@@ -1,3 +1,4 @@
+import is from '@sindresorhus/is';
 import * as fs from 'fs-extra';
 import { isAbsolute, join, parse } from 'upath';
 import { getAdminConfig } from '../../config/admin';
@@ -65,7 +66,9 @@ export async function renameLocalFile(
 
 // istanbul ignore next
 export async function ensureDir(dirName: string): Promise<void> {
-  await fs.ensureDir(dirName);
+  if (is.nonEmptyString(dirName)) {
+    await fs.ensureDir(dirName);
+  }
 }
 
 // istanbul ignore next