diff --git a/app/api/me/theme/route.ts b/app/api/me/theme/route.ts
index f50a96a..de73ffd 100644
--- a/app/api/me/theme/route.ts
+++ b/app/api/me/theme/route.ts
@@ -12,9 +12,9 @@ import { postgresClient } from '@/lib/services/postgres-client';
 // Validation: the input theme must be one of: 'light', 'dark', 'system'.
 // Anything else is rejected with 400 before touching the database.
 //
-// NOTE: The UPDATE statement uses `updated_at` (snake_case, unquoted) — the
-// actual column in migration 012_create_auth_tables.sql. This matches the
-// working precedent in app/api/settings/profile/route.ts (not the timezone route).
+// NOTE: The UPDATE statement uses `"updatedAt"` (quoted camelCase) — that is
+// the actual column name in the Better Auth `"user"` table (verified via psql).
+// Matches the working precedent in app/api/me/timezone/route.ts.
 
 const ALLOWED_THEMES = new Set(['light', 'dark', 'system'] as const);
 
@@ -74,9 +74,9 @@ export async function PUT(request: NextRequest): Promise<NextResponse> {
 
   try {
     // Authoritative write target: session.user.id. NO userId from body.
-    // updated_at is unquoted snake_case — matches migration 012 schema.
+    // "updatedAt" is quoted camelCase — matches Better Auth schema (verified).
     const result = await postgresClient.query<{ theme: string }>(
-      'UPDATE "user" SET theme = $1, updated_at = NOW() WHERE id = $2 RETURNING theme',
+      'UPDATE "user" SET theme = $1, "updatedAt" = NOW() WHERE id = $2 RETURNING theme',
       [candidate, session!.user.id],
     );
     if (result.rowCount === 0) {