diff --git a/packages/backend-test-utils/package.json b/packages/backend-test-utils/package.json
index da626d3786..0a91508400 100644
--- a/packages/backend-test-utils/package.json
+++ b/packages/backend-test-utils/package.json
@@ -46,6 +46,7 @@
     "@backstage/backend-common": "workspace:^",
     "@backstage/backend-plugin-api": "workspace:^",
     "@backstage/config": "workspace:^",
+    "@backstage/errors": "workspace:^",
     "@backstage/plugin-auth-node": "workspace:^",
     "@backstage/types": "workspace:^",
     "better-sqlite3": "^8.0.0",
diff --git a/packages/backend-test-utils/src/filesystem/MockDirectory.test.ts b/packages/backend-test-utils/src/filesystem/MockDirectory.test.ts
index 562acb3a8a..a7fe1815b2 100644
--- a/packages/backend-test-utils/src/filesystem/MockDirectory.test.ts
+++ b/packages/backend-test-utils/src/filesystem/MockDirectory.test.ts
@@ -16,7 +16,11 @@
 
 import fs from 'fs-extra';
 import os from 'os';
-import { relative as relativePath } from 'path';
+import {
+  join as joinPath,
+  resolve as resolvePath,
+  relative as relativePath,
+} from 'path';
 import { MockDirectory } from './MockDirectory';
 
 describe('MockDirectory', () => {
@@ -27,7 +31,9 @@ describe('MockDirectory', () => {
   it('should resolve paths', () => {
     expect(mockDir.path).toEqual(expect.any(String));
     expect(relativePath(mockDir.path, mockDir.resolve('a'))).toBe('a');
-    expect(relativePath(mockDir.path, mockDir.resolve('a/b/c'))).toBe('a/b/c');
+    expect(relativePath(mockDir.path, mockDir.resolve('a/b/c'))).toBe(
+      joinPath('a', 'b', 'c'),
+    );
   });
 
   it('should remove itself', async () => {
@@ -267,14 +273,15 @@ describe('MockDirectory', () => {
   });
 
   it('should reject non-child paths', async () => {
+    const path = resolvePath('/root/a.txt');
     await expect(mockDir.setContent({ '/root/a.txt': 'a' })).rejects.toThrow(
-      "Provided path must resolve to a child path of the mock directory, got '/root/a.txt'",
+      `Provided path must resolve to a child path of the mock directory, got '${path}'`,
     );
     await expect(mockDir.addContent({ '/root/a.txt': 'a' })).rejects.toThrow(
-      "Provided path must resolve to a child path of the mock directory, got '/root/a.txt'",
+      `Provided path must resolve to a child path of the mock directory, got '${path}'`,
     );
     await expect(mockDir.content({ path: '/root/a.txt' })).rejects.toThrow(
-      "Provided path must resolve to a child path of the mock directory, got '/root/a.txt'",
+      `Provided path must resolve to a child path of the mock directory, got '${path}'`,
     );
   });
 
diff --git a/packages/backend-test-utils/src/filesystem/MockDirectory.ts b/packages/backend-test-utils/src/filesystem/MockDirectory.ts
index 5553982484..371a315f22 100644
--- a/packages/backend-test-utils/src/filesystem/MockDirectory.ts
+++ b/packages/backend-test-utils/src/filesystem/MockDirectory.ts
@@ -28,6 +28,7 @@ import {
   win32,
   posix,
 } from 'path';
+import { isError } from '@backstage/errors';
 
 /**
  * The content of a mock directory represented by a nested object structure.
@@ -334,7 +335,16 @@ export class MockDirectory {
    * Removes the mock directory and all its contents.
    */
   remove = async (): Promise<void> => {
-    await fs.rm(this.#root, { recursive: true, force: true });
+    try {
+      await fs.rm(this.#root, { recursive: true, force: true });
+    } catch (error: unknown) {
+      if (isError(error) && error.code === 'ENOTEMPTY') {
+        // Windows can be a bit flaky, give it another go
+        await fs.rm(this.#root, { recursive: true, force: true });
+      } else {
+        throw error;
+      }
+    }
   };
 
   #transformInput(input: MockDirectoryContent[string]): MockEntry[] {
diff --git a/yarn.lock b/yarn.lock
index dc8e58da96..20922a9959 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3642,6 +3642,7 @@ __metadata:
     "@backstage/backend-plugin-api": "workspace:^"
     "@backstage/cli": "workspace:^"
     "@backstage/config": "workspace:^"
+    "@backstage/errors": "workspace:^"
     "@backstage/plugin-auth-node": "workspace:^"
     "@backstage/types": "workspace:^"
     "@types/supertest": ^2.0.8