diff --git a/Source/Game/Entities/Object/Update/UpdateFields.cs b/Source/Game/Entities/Object/Update/UpdateFields.cs
index ba32f4324..65240bfe0 100644
--- a/Source/Game/Entities/Object/Update/UpdateFields.cs
+++ b/Source/Game/Entities/Object/Update/UpdateFields.cs
@@ -3471,6 +3471,8 @@ namespace Game.Entities
     {
         public static int ExploredZonesSize;
         public static int ExploredZonesBits;
+        public static int QuestCompletedBitsSize;
+        public static int QuestCompletedBitsPerBlock;
 
         public UpdateField<bool> BackpackAutoSortDisabled = new(0, 1);
         public UpdateField<bool> BankAutoSortDisabled = new(0, 2);
@@ -3602,6 +3604,9 @@ namespace Game.Entities
         {
             ExploredZonesSize = ExploredZones.GetSize();
             ExploredZonesBits = sizeof(ulong) * 8;
+
+            QuestCompletedBitsSize = QuestCompleted.GetSize();
+            QuestCompletedBitsPerBlock = sizeof(ulong) * 8;
         }
 
         public void WriteCreate(WorldPacket data, UpdateFieldFlag fieldVisibilityFlags, Player owner, Player receiver)
diff --git a/Source/Game/Entities/Player/Player.Quest.cs b/Source/Game/Entities/Player/Player.Quest.cs
index 648dc9797..20948d6cb 100644
--- a/Source/Game/Entities/Player/Player.Quest.cs
+++ b/Source/Game/Entities/Player/Player.Quest.cs
@@ -2218,11 +2218,11 @@ namespace Game.Entities
             if (questBit == 0)
                 return;
 
-            uint fieldOffset = (questBit - 1) >> 6;
+            uint fieldOffset = (questBit - 1) >> ActivePlayerData.QuestCompletedBitsPerBlock;
             if (fieldOffset >= PlayerConst.QuestsCompletedBitsSize)
                 return;
 
-            ulong flag = 1ul << (((int)questBit - 1) & 63);
+            ulong flag = 1ul << (((int)questBit - 1) % ActivePlayerData.QuestCompletedBitsPerBlock);
             if (completed)
                 SetUpdateFieldFlagValue(ref m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.QuestCompleted, (int)fieldOffset), flag);
             else