diff --git a/api/QuestionsApi/Services/CreditStore.cs b/api/QuestionsApi/Services/CreditStore.cs
index 5914ed0..5e6ee86 100644
--- a/api/QuestionsApi/Services/CreditStore.cs
+++ b/api/QuestionsApi/Services/CreditStore.cs
@@ -66,8 +66,14 @@ public sealed class CreditStore
             value => value.UserId == userId,
             Builders<UserCreditAccount>.Update
                 .SetOnInsert(value => value.UserId, userId)
+                .SetOnInsert(value => value.Credits, 0)
+                .SetOnInsert(value => value.RecentEarnings, [])
                 .SetOnInsert(value => value.UpdatedUtc, now),
             new UpdateOptions { IsUpsert = true });
+        await _accounts.UpdateOneAsync(
+            Builders<UserCreditAccount>.Filter.Eq(value => value.UserId, userId) &
+            Builders<UserCreditAccount>.Filter.Exists(nameof(UserCreditAccount.RecentEarnings), false),
+            Builders<UserCreditAccount>.Update.Set(value => value.RecentEarnings, []));
         var cutoff = now - CreditEconomy.EarningWindow;
         await _accounts.UpdateOneAsync(
             value => value.UserId == userId,