diff --git a/src/ssl-key-storage.test.ts b/src/ssl-key-storage.test.ts
index 017475155..00075333a 100644
--- a/src/ssl-key-storage.test.ts
+++ b/src/ssl-key-storage.test.ts
@@ -39,11 +39,12 @@ import * as path from 'path';
 import { mockExecaFn } from './test-helpers/mock-execa.test-utils';
 import {
   mountSslTmpfs,
-  secureWipeFile,
   cleanupSslKeyMaterial,
+  testHelpers,
 } from './ssl-key-storage';
 
 const FAKE_FD = 42;
+const { secureWipeFile } = testHelpers;
 
 describe('ssl-key-storage', () => {
   beforeEach(() => {
diff --git a/src/ssl-key-storage.ts b/src/ssl-key-storage.ts
index 10b5d27ce..097b2c905 100644
--- a/src/ssl-key-storage.ts
+++ b/src/ssl-key-storage.ts
@@ -77,9 +77,8 @@ export async function unmountSslTmpfs(sslDir: string): Promise<void> {
  * cannot be guaranteed on all filesystems (for example, journaling/COW).
  *
  * @param filePath - Path to the file to securely wipe
- * @internal Exported for testing
  */
-export function secureWipeFile(filePath: string): void {
+function secureWipeFile(filePath: string): void {
   let fd: number | undefined;
 
   try {
@@ -167,3 +166,7 @@ export function cleanupSslKeyMaterial(workDir: string): void {
 
   logger.debug('SSL key material securely wiped');
 }
+
+/** @internal Exposed for unit tests. */
+// ts-prune-ignore-next
+export const testHelpers = { secureWipeFile };