diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d8167c..1d4e3f5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Fixed
+- Fixed TypeScript build error in `frontend/src/app/accounts/page.tsx`: replaced non-existent `account.username` with `account.email_address` (the backend intentionally excludes `username` from API responses for security)
 - Upgraded Node.js base image in `frontend/Dockerfile` from `node:18-alpine` to `node:20-alpine` to satisfy the Node.js >= 20.9.0 requirement for Next.js and fix Docker build failures
 - Removed `actions/attest-build-provenance` step and associated `id-token: write` / `attestations: write` permissions from the CI `build` job — this action is not available for private user-owned repositories and caused every build to fail
 - Downgraded `eslint` from `^10` to `^9` in the frontend to resolve `TypeError: contextOrFilename.getFilename is not a function` caused by ESLint 10 removing the `getFilename()` API used by `eslint-plugin-react` bundled in `eslint-config-next`
diff --git a/frontend/src/app/accounts/page.tsx b/frontend/src/app/accounts/page.tsx
index 95dda97..0a69fe8 100644
--- a/frontend/src/app/accounts/page.tsx
+++ b/frontend/src/app/accounts/page.tsx
@@ -77,7 +77,7 @@ export default function AccountsPage() {
                         <h3 className="text-lg font-semibold text-gray-900 mb-1">
                           {account.name}
                         </h3>
-                        <p className="text-sm text-gray-500">{account.username}</p>
+                        <p className="text-sm text-gray-500">{account.email_address}</p>
                       </div>
                       <div className="flex items-center gap-2">
                         {account.is_enabled ? (
@@ -113,17 +113,17 @@ export default function AccountsPage() {
                       </div>
                     </div>
 
-                    {account.last_checked_at && (
+                    {account.last_check_at && (
                       <div className="mb-4 text-xs text-gray-500">
-                        Last checked: {new Date(account.last_checked_at).toLocaleString()}
+                        Last checked: {new Date(account.last_check_at).toLocaleString()}
                       </div>
                     )}
 
-                    {account.last_error && (
+                    {account.last_error_message && (
                       <div className="mb-4 p-3 bg-red-50 border border-red-200 rounded-md">
                         <div className="flex items-start">
                           <AlertTriangle className="h-4 w-4 text-red-500 mr-2 mt-0.5 flex-shrink-0" />
-                          <p className="text-xs text-red-700">{account.last_error}</p>
+                          <p className="text-xs text-red-700">{account.last_error_message}</p>
                         </div>
                       </div>
                     )}