diff --git a/CHANGELOG.md b/CHANGELOG.md
index b6d2bbe..951fd9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- version list -->
 
+## [Unreleased]
+
+### Fixed
+
+- Convert `frontend/jest.config.js` to `jest.config.mjs` using ES module `import`/`export` syntax to resolve ESLint `@typescript-eslint/no-require-imports` error.
+
 ## v0.5.0 (2026-03-28)
 
 ### Features
diff --git a/docs/TODO.md b/docs/TODO.md
index 02002c5..155921b 100644
--- a/docs/TODO.md
+++ b/docs/TODO.md
@@ -4,6 +4,7 @@ Comprehensive task breakdown for repository improvements and production readines
 
 ## ✅ Recently Completed
 
+- [x] **ESLint fix**: Converted `frontend/jest.config.js` to `jest.config.mjs` (ES module syntax) to resolve `@typescript-eslint/no-require-imports` lint error.
 - [x] **Codecov integration**: Added Codecov coverage reporting with `CODECOV_TOKEN` authentication. Set up Jest for frontend tests with lcov coverage, updated CI to collect and upload both backend (XML via pytest-cov) and frontend (lcov via Jest) coverage reports to Codecov with separate `backend` and `frontend` flags.
 - [x] **IMAP: fix all emails appearing empty** — `aioimaplib` stores RFC822 literal data as `bytearray`, not `bytes`. The extraction loop was checking `isinstance(line, bytes)` which returns `False` for `bytearray`, so every email body was silently skipped. Fixed to accept both types and convert to `bytes`. Affected T-Online, GMX, and all IMAP accounts.
 - [x] **CI: fix safety scan EOF error** — replaced `safety scan --json` (Safety CLI v3 requires interactive login) with `pip-audit` (no auth required, maintained by PyPA).
diff --git a/frontend/jest.config.js b/frontend/jest.config.mjs
similarity index 82%
rename from frontend/jest.config.js
rename to frontend/jest.config.mjs
index d7c1fe5..547dfae 100644
--- a/frontend/jest.config.js
+++ b/frontend/jest.config.mjs
@@ -1,4 +1,4 @@
-const nextJest = require('next/jest');
+import nextJest from 'next/jest.js';
 
 const createJestConfig = nextJest({
   dir: './',
@@ -19,4 +19,4 @@ const customJestConfig = {
   ],
 };
 
-module.exports = createJestConfig(customJestConfig);
+export default createJestConfig(customJestConfig);