diff --git a/packages/backend-test-utils/src/files/DirectoryMocker.ts b/packages/backend-test-utils/src/files/DirectoryMocker.ts
index 593b2790c4..0422969762 100644
--- a/packages/backend-test-utils/src/files/DirectoryMocker.ts
+++ b/packages/backend-test-utils/src/files/DirectoryMocker.ts
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import os from 'os';
 import { isChildPath, resolveSafeChildPath } from '@backstage/backend-common';
 import fs from 'fs-extra';
 import textextensions from 'textextensions';
@@ -83,6 +84,21 @@ export class DirectoryMocker {
     return mocker;
   }
 
+  static mockOsTmpDir() {
+    const mocker = DirectoryMocker.create();
+    const origTmpdir = os.tmpdir;
+    os.tmpdir = () => mocker.path;
+
+    try {
+      afterAll(() => {
+        os.tmpdir = origTmpdir;
+      });
+    } catch {
+      /* ignore */
+    }
+    return mocker;
+  }
+
   readonly #root: string;
 
   private constructor(root: string) {