diff --git a/MinecraftClient/McClient.cs b/MinecraftClient/McClient.cs
index d608cc5d..2f517021 100644
--- a/MinecraftClient/McClient.cs
+++ b/MinecraftClient/McClient.cs
@@ -1243,8 +1243,7 @@ namespace MinecraftClient
             if (inventories.ContainsKey(windowId) && inventories[windowId].Items.ContainsKey(slotId))
                 item = inventories[windowId].Items[slotId];
 
-            // Inventory update must be after sending packet
-            bool result = handler.SendWindowAction(windowId, slotId, action, item, inventories[windowId].Items, inventories[windowId].StateID);
+            List<Tuple<short, Item>> changedSlots = new List<Tuple<short, Item>>(); // List<Slot ID, Changed Items>
 
             // Update our inventory base on action type
             var inventory = GetInventory(windowId);
@@ -1295,6 +1294,8 @@ namespace MinecraftClient
                                 inventory.Items[slotId] = playerInventory.Items[-1];
                                 playerInventory.Items.Remove(-1);
                             }
+
+                            changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                         }
                         else
                         {
@@ -1307,6 +1308,8 @@ namespace MinecraftClient
                                 // Put target slot item to cursor
                                 playerInventory.Items[-1] = inventory.Items[slotId];
                                 inventory.Items.Remove(slotId);
+
+                                changedSlots.Add(new Tuple<short, Item>((short)slotId, null));
                             }
                         }
                         break;
@@ -1385,6 +1388,7 @@ namespace MinecraftClient
                                 }
                             }
                         }
+                        changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                         break;
                     case WindowActionType.ShiftClick:
                         if (slotId == 0) break;
@@ -1412,6 +1416,7 @@ namespace MinecraftClient
                             // If hotbar already have same item, will put on it first until every stack are full
                             // If no more same item , will put on the first empty slot (smaller slot id)
                             // If inventory full, item will not move
+                            int itemCount = inventory.Items[slotId].Count;
                             if (slotId <= upperEndSlot)
                             {
                                 // Clicked slot is on upper side inventory, put it to hotbar
@@ -1431,11 +1436,16 @@ namespace MinecraftClient
                                             // Can fit into the stack
                                             inventory.Items[_item.Key].Count += inventory.Items[slotId].Count;
                                             inventory.Items.Remove(slotId);
+
+                                            changedSlots.Add(new Tuple<short, Item>((short)_item.Key, inventory.Items[_item.Key]));
+                                            changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                                         }
                                         else
                                         {
                                             inventory.Items[slotId].Count -= spaceLeft;
                                             inventory.Items[_item.Key].Count = inventory.Items[_item.Key].Type.StackCount();
+
+                                            changedSlots.Add(new Tuple<short, Item>((short)_item.Key, inventory.Items[_item.Key]));
                                         }
                                     }
                                 }
@@ -1454,6 +1464,13 @@ namespace MinecraftClient
                                         var itemTmp = inventory.Items[slotId];
                                         inventory.Items[emptySlot] = new Item(itemTmp.Type, itemTmp.Count, itemTmp.NBT);
                                         inventory.Items.Remove(slotId);
+
+                                        changedSlots.Add(new Tuple<short, Item>((short)emptySlot, inventory.Items[emptySlot]));
+                                        changedSlots.Add(new Tuple<short, Item>((short)slotId, null));
+                                    }
+                                    else if (inventory.Items[slotId].Count != itemCount)
+                                    {
+                                        changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                                     }
                                 }
                             }
@@ -1477,11 +1494,16 @@ namespace MinecraftClient
                                             // Can fit into the stack
                                             inventory.Items[_item.Key].Count += inventory.Items[slotId].Count;
                                             inventory.Items.Remove(slotId);
+
+                                            changedSlots.Add(new Tuple<short, Item>((short)_item.Key, inventory.Items[_item.Key]));
+                                            changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                                         }
                                         else
                                         {
                                             inventory.Items[slotId].Count -= spaceLeft;
                                             inventory.Items[_item.Key].Count = inventory.Items[_item.Key].Type.StackCount();
+
+                                            changedSlots.Add(new Tuple<short, Item>((short)_item.Key, inventory.Items[_item.Key]));
                                         }
                                     }
                                 }
@@ -1501,6 +1523,13 @@ namespace MinecraftClient
                                         var itemTmp = inventory.Items[slotId];
                                         inventory.Items[emptySlot] = new Item(itemTmp.Type, itemTmp.Count, itemTmp.NBT);
                                         inventory.Items.Remove(slotId);
+
+                                        changedSlots.Add(new Tuple<short, Item>((short)emptySlot, inventory.Items[emptySlot]));
+                                        changedSlots.Add(new Tuple<short, Item>((short)slotId, null));
+                                    }
+                                    else if (inventory.Items[slotId].Count != itemCount)
+                                    {
+                                        changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                                     }
                                 }
                             }
@@ -1512,14 +1541,18 @@ namespace MinecraftClient
 
                         if (inventory.Items[slotId].Count <= 0)
                             inventory.Items.Remove(slotId);
+
+                        changedSlots.Add(new Tuple<short, Item>((short)slotId, inventory.Items[slotId]));
                         break;
                     case WindowActionType.DropItemStack:
                         inventory.Items.Remove(slotId);
+
+                        changedSlots.Add(new Tuple<short, Item>((short)slotId, null));
                         break;
                 }
             }
 
-            return result;
+            return handler.SendWindowAction(windowId, slotId, action, item, changedSlots, inventories[windowId].StateID);
         }
 
         /// <summary>
@@ -2046,8 +2079,11 @@ namespace MinecraftClient
         /// <param name="inventoryID">Window ID</param>
         /// <param name="slotID">Slot ID</param>
         /// <param name="item">Item (may be null for empty slot)</param>
-        public void OnSetSlot(byte inventoryID, short slotID, Item item)
+        public void OnSetSlot(byte inventoryID, short slotID, Item item, int stateId)
         {
+            if (inventories.ContainsKey(inventoryID))
+                inventories[inventoryID].StateID = stateId;
+
             // Handle inventoryID -2 - Add item to player inventory without animation
             if (inventoryID == 254)
                 inventoryID = 0;
diff --git a/MinecraftClient/Protocol/Handlers/Protocol16.cs b/MinecraftClient/Protocol/Handlers/Protocol16.cs
index c7e0b9ef..0f30bfce 100644
--- a/MinecraftClient/Protocol/Handlers/Protocol16.cs
+++ b/MinecraftClient/Protocol/Handlers/Protocol16.cs
@@ -720,7 +720,7 @@ namespace MinecraftClient.Protocol.Handlers
             return false; //Currently not implemented
         }
 
-        public bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, Dictionary<int, Item> Items, int stateId)
+        public bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, List<Tuple<short, Item>> changedSlots, int stateId)
         {
             return false; //Currently not implemented
         }
diff --git a/MinecraftClient/Protocol/Handlers/Protocol18.cs b/MinecraftClient/Protocol/Handlers/Protocol18.cs
index abc4f2bb..cd8f831e 100644
--- a/MinecraftClient/Protocol/Handlers/Protocol18.cs
+++ b/MinecraftClient/Protocol/Handlers/Protocol18.cs
@@ -917,7 +917,7 @@ namespace MinecraftClient.Protocol.Handlers
 
                                 short slotID = dataTypes.ReadNextShort(packetData);
                                 Item item = dataTypes.ReadNextItemSlot(packetData, itemPalette);
-                                handler.OnSetSlot(windowID, slotID, item);
+                                handler.OnSetSlot(windowID, slotID, item, stateId);
                             }
                             break;
                         case PacketTypesIn.WindowConfirmation:
@@ -1967,7 +1967,7 @@ namespace MinecraftClient.Protocol.Handlers
             catch (ObjectDisposedException) { return false; }
         }
 
-        public bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, Dictionary<int, Item> items, int stateId)
+        public bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, List<Tuple<short, Item>> changedSlots, int stateId)
         {
             try
             {
@@ -2004,51 +2004,48 @@ namespace MinecraftClient.Protocol.Handlers
 
                 List<byte> packet = new List<byte>();
 
-                log.Info("Window id: " + windowId + " - State id: " + stateId + " - Slot id: " + slotId + " - Mode: " + mode);
-                log.Info("Bytes > " + (byte)windowId + " - State id: " + dataTypes.ByteArrayToString(dataTypes.GetVarInt(stateId)) + " - Slot id: " + dataTypes.ByteArrayToString(dataTypes.GetVarInt(slotId)) + " - Mode: " + dataTypes.ByteArrayToString(dataTypes.GetVarInt(mode)));
-
-                packet.Add((byte)windowId);
+                packet.Add((byte)windowId); // Window ID
 
                 // 1.18+
                 if (protocolversion >= MC1181Version)
                 {
-                    packet.AddRange(dataTypes.GetVarInt(stateId));
-                    packet.AddRange(dataTypes.GetShort((short)slotId));
+                    packet.AddRange(dataTypes.GetVarInt(stateId)); // State ID
+                    packet.AddRange(dataTypes.GetShort((short)slotId)); // Slot ID
                 }
                 // 1.17.1
                 else if (protocolversion == MC1171Version)
                 {
-                    packet.AddRange(dataTypes.GetShort((short)slotId));
-                    packet.AddRange(dataTypes.GetVarInt(stateId));
+                    packet.AddRange(dataTypes.GetShort((short)slotId)); // Slot ID
+                    packet.AddRange(dataTypes.GetVarInt(stateId)); // State ID
                 }
                 // Older
                 else
                 {
-                    packet.AddRange(dataTypes.GetShort((short)slotId));
+                    packet.AddRange(dataTypes.GetShort((short)slotId)); // Slot ID
                 }
 
-                packet.Add(button);
-                if (protocolversion < MC117Version) packet.AddRange(dataTypes.GetShort(actionNumber));
+                packet.Add(button); // Button
+
+                if (protocolversion < MC117Version)
+                    packet.AddRange(dataTypes.GetShort(actionNumber));
+
                 if (protocolversion >= MC19Version)
-                    packet.AddRange(dataTypes.GetVarInt(mode));
+                    packet.AddRange(dataTypes.GetVarInt(mode)); // Mode
                 else packet.Add(mode);
 
                 // 1.17+
                 if (protocolversion >= MC117Version)
                 {
-                    byte[] arrayOfSlots = dataTypes.GetSlotsArray(items, itemPalette);
-
-                    log.Info("Length: " + dataTypes.ByteArrayToString(dataTypes.GetVarInt(arrayOfSlots.Length)) + " (" + arrayOfSlots.Length + ")");
-                    log.Info("Array: " + dataTypes.ByteArrayToString(arrayOfSlots));
-
-                    packet.AddRange(dataTypes.GetVarInt(arrayOfSlots.Length));
-                    packet.AddRange(arrayOfSlots);
+                    packet.AddRange(dataTypes.GetVarInt(changedSlots.Count)); // Length of the array
+                    foreach (var slot in changedSlots)
+                    {
+                        packet.AddRange(dataTypes.GetShort(slot.Item1)); // slot ID
+                        packet.AddRange(dataTypes.GetItemSlot(slot.Item2, itemPalette)); // slot Data
+                    }
                 }
 
                 packet.AddRange(dataTypes.GetItemSlot(item, itemPalette)); // Carried item (Clicked item)
 
-                log.Info("Packet data: " + dataTypes.ByteArrayToString(packet.ToArray()));
-
                 SendPacket(PacketTypesOut.ClickWindow, packet);
                 return true;
             }
diff --git a/MinecraftClient/Protocol/IMinecraftCom.cs b/MinecraftClient/Protocol/IMinecraftCom.cs
index 97aaca35..487e8190 100644
--- a/MinecraftClient/Protocol/IMinecraftCom.cs
+++ b/MinecraftClient/Protocol/IMinecraftCom.cs
@@ -162,10 +162,12 @@ namespace MinecraftClient.Protocol
         /// </summary>
         /// <param name="windowId">Id of the window being clicked</param>
         /// <param name="slotId">Id of the clicked slot</param>
-        /// <param name="buttom">Action to perform</param>
+        /// <param name="action">Action to perform</param>
         /// <param name="item">Item in the clicked slot</param>
+        /// <param name="changedSlots">Slots that have been changed in this event: List<SlotID, Changed Items> </param>
+        /// <param name="stateId">Inventory's stateId</param>
         /// <returns>True if packet was successfully sent</returns>
-        bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, Dictionary<int, Item> Items, int stateId);
+        bool SendWindowAction(int windowId, int slotId, WindowActionType action, Item item, List<Tuple<short, Item>> changedSlots, int stateId);
 
         /// <summary>
         /// Request Creative Mode item creation into regular/survival Player Inventory
diff --git a/MinecraftClient/Protocol/IMinecraftComHandler.cs b/MinecraftClient/Protocol/IMinecraftComHandler.cs
index 4ca8faf9..3da38c94 100644
--- a/MinecraftClient/Protocol/IMinecraftComHandler.cs
+++ b/MinecraftClient/Protocol/IMinecraftComHandler.cs
@@ -272,7 +272,8 @@ namespace MinecraftClient.Protocol
         /// <param name="inventoryID">Window ID</param>
         /// <param name="slotID">Slot ID</param>
         /// <param name="item">Item (may be null for empty slot)</param>
-        void OnSetSlot(byte inventoryID, short slotID, Item item);
+        /// <param name="stateId">State ID</param>
+        void OnSetSlot(byte inventoryID, short slotID, Item item, int stateId);
 
         /// <summary>
         /// Called when player health or hunger changed.