diff --git a/packages/backend/src/lib/gamification.ts b/packages/backend/src/lib/gamification.ts
index a6c3a51..3e6fd82 100644
--- a/packages/backend/src/lib/gamification.ts
+++ b/packages/backend/src/lib/gamification.ts
@@ -195,7 +195,9 @@ export async function checkAchievements(db: DB, userId: string, category?: strin
         .update(user_achievements)
         .set({
           progress,
-          date_unlocked: isUnlocked ? existing[0].date_unlocked || new Date() : null,
+          date_unlocked: isUnlocked
+            ? (existing[0].date_unlocked ?? new Date())
+            : existing[0].date_unlocked,
         })
         .where(
           and(