diff --git a/PKHeX.Core/PKM/BK4.cs b/PKHeX.Core/PKM/BK4.cs
index ae2ecf701..e588578ed 100644
--- a/PKHeX.Core/PKM/BK4.cs
+++ b/PKHeX.Core/PKM/BK4.cs
@@ -48,9 +48,9 @@ public BK4(byte[] data) : base(data)
         public override PKM Clone() => new BK4((byte[])Data.Clone());
 
         // Structure
-        public override uint PID { get => ReadUInt16BigEndian(Data.AsSpan(0x00)); set => WriteUInt32BigEndian(Data.AsSpan(0x00), value); }
-        public override ushort Sanity { get => ReadUInt16BigEndian(Data.AsSpan(0x04)); set => WriteUInt32BigEndian(Data.AsSpan(0x04), value); }
-        public override ushort Checksum { get => ReadUInt16BigEndian(Data.AsSpan(0x06)); set => WriteUInt32BigEndian(Data.AsSpan(0x06), value); }
+        public override uint PID { get => ReadUInt32BigEndian(Data.AsSpan(0x00)); set => WriteUInt32BigEndian(Data.AsSpan(0x00), value); }
+        public override ushort Sanity { get => ReadUInt16BigEndian(Data.AsSpan(0x04)); set => WriteUInt16BigEndian(Data.AsSpan(0x04), value); }
+        public override ushort Checksum { get => ReadUInt16BigEndian(Data.AsSpan(0x06)); set => WriteUInt16BigEndian(Data.AsSpan(0x06), value); }
 
         #region Block A
         public override int Species { get => ReadUInt16BigEndian(Data.AsSpan(0x08)); set => WriteUInt16BigEndian(Data.AsSpan(0x08), (ushort)value); }
diff --git a/PKHeX.Core/Saves/Substructures/Inventory/InventoryPouch3GC.cs b/PKHeX.Core/Saves/Substructures/Inventory/InventoryPouch3GC.cs
index 3b51665af..e72f0a851 100644
--- a/PKHeX.Core/Saves/Substructures/Inventory/InventoryPouch3GC.cs
+++ b/PKHeX.Core/Saves/Substructures/Inventory/InventoryPouch3GC.cs
@@ -36,9 +36,10 @@ public override void SetPouch(Span<byte> data)
             var span = data[Offset..];
             for (int i = 0; i < Items.Length; i++)
             {
-                var item = span.Slice(i * 4, 4);
-                WriteUInt32BigEndian(item,      (ushort)Items[i].Index);
-                WriteUInt32BigEndian(item[2..], (ushort)Items[i].Count);
+                var item = Items[i];
+                var slice = span.Slice(i * 4, 4);
+                WriteUInt16BigEndian(slice,      (ushort)item.Index);
+                WriteUInt16BigEndian(slice[2..], (ushort)item.Count);
             }
         }
     }