diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_2to1_13_1/packets/InventoryPackets.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_2to1_13_1/packets/InventoryPackets.java
index f9ca2746f..2a21704c5 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_2to1_13_1/packets/InventoryPackets.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13_2to1_13_1/packets/InventoryPackets.java
@@ -31,7 +31,7 @@ public class InventoryPackets {
         protocol.registerClientbound(ClientboundPackets1_13.SET_SLOT, new PacketRemapper() {
             @Override
             public void registerMap() {
-                map(Type.BYTE); // 0 - Window ID
+                map(Type.UNSIGNED_BYTE); // 0 - Window ID
                 map(Type.SHORT); // 1 - Slot ID
                 map(Type.FLAT_ITEM, Type.FLAT_VAR_INT_ITEM); // 2 - Slot Value
             }
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java
index dbc826b66..b07a7e0d1 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_13to1_12_2/packets/InventoryPackets.java
@@ -61,7 +61,7 @@ public class InventoryPackets extends ItemRewriter<Protocol1_13To1_12_2> {
         protocol.registerClientbound(ClientboundPackets1_12_1.SET_SLOT, new PacketRemapper() {
             @Override
             public void registerMap() {
-                map(Type.BYTE); // 0 - Window ID
+                map(Type.UNSIGNED_BYTE); // 0 - Window ID
                 map(Type.SHORT); // 1 - Slot ID
                 map(Type.ITEM, Type.FLAT_ITEM); // 2 - Slot Value
 
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/InventoryPackets.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/InventoryPackets.java
index 35e9aefae..8256285a1 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/InventoryPackets.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_9to1_8/packets/InventoryPackets.java
@@ -106,7 +106,7 @@ public class InventoryPackets {
         protocol.registerClientbound(ClientboundPackets1_8.SET_SLOT, new PacketRemapper() {
             @Override
             public void registerMap() {
-                map(Type.BYTE); // 0 - Window ID
+                map(Type.UNSIGNED_BYTE); // 0 - Window ID
                 map(Type.SHORT); // 1 - Slot ID
                 map(Type.ITEM); // 2 - Slot Value
                 handler(new PacketHandler() {
@@ -123,7 +123,7 @@ public class InventoryPackets {
                             EntityTracker1_9 entityTracker = wrapper.user().getEntityTracker(Protocol1_9To1_8.class);
 
                             short slotID = wrapper.get(Type.SHORT, 0);
-                            short windowId = wrapper.get(Type.BYTE, 0);
+                            short windowId = wrapper.get(Type.UNSIGNED_BYTE, 0);
 
                             // Store item in slot
                             inventoryTracker.setItemId(windowId, slotID, stack == null ? 0 : stack.identifier());
diff --git a/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java b/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
index 315d90111..900c4b2e6 100644
--- a/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
+++ b/common/src/main/java/com/viaversion/viaversion/rewriter/ItemRewriter.java
@@ -70,7 +70,7 @@ public abstract class ItemRewriter<T extends Protocol> extends RewriterBase<T> i
         protocol.registerClientbound(packetType, new PacketRemapper() {
             @Override
             public void registerMap() {
-                map(Type.BYTE); // 0 - Window ID
+                map(Type.UNSIGNED_BYTE); // 0 - Window ID
                 map(Type.SHORT); // 1 - Slot ID
                 map(type); // 2 - Slot Value