diff --git a/ClassicalSharp/Blocks/Block.cs b/ClassicalSharp/Blocks/Block.cs
index a67ec53ff..2607264b0 100644
--- a/ClassicalSharp/Blocks/Block.cs
+++ b/ClassicalSharp/Blocks/Block.cs
@@ -101,7 +101,7 @@ namespace ClassicalSharp {
 		public const int CpeCount = MaxCpeBlock + 1;
 		
 		#if USE16_BIT
-		public const BlockID MaxDefinedBlock = 0xFFF;
+		public const BlockID MaxDefinedBlock = 0x3FF;
 		#else
 		public const BlockID MaxDefinedBlock =  0xFF;
 		#endif
diff --git a/ClassicalSharp/Blocks/BlockInfo.Culling.cs b/ClassicalSharp/Blocks/BlockInfo.Culling.cs
index 276159715..7c49d397c 100644
--- a/ClassicalSharp/Blocks/BlockInfo.Culling.cs
+++ b/ClassicalSharp/Blocks/BlockInfo.Culling.cs
@@ -100,7 +100,7 @@ namespace ClassicalSharp {
 		/// should be drawn with the neighbour 'other' present on the other side of the face. </summary>
 		public static bool IsFaceHidden(BlockID block, BlockID other, int tileSide) {
 			#if USE16_BIT
-			return (hidden[(block << 12) | other] & (1 << tileSide)) != 0;
+			return (hidden[(block << 10) | other] & (1 << tileSide)) != 0;
 			#else
 			return (hidden[(block << 8) | other] & (1 << tileSide)) != 0;
 			#endif
diff --git a/ClassicalSharp/Game/Inventory.cs b/ClassicalSharp/Game/Inventory.cs
index d61d1a7e2..ea231371b 100644
--- a/ClassicalSharp/Game/Inventory.cs
+++ b/ClassicalSharp/Game/Inventory.cs
@@ -107,7 +107,7 @@ namespace ClassicalSharp {
 		
 		BlockID DefaultMapping(int i) {
 #if USE16_BIT
-			if ((i >= Block.CpeCount && i < 256) || i == Block.Air) return Block.Air;
+			if ((i >= Block.CpeCount) || i == Block.Air) return Block.Air;
 #else
 			if (i >= Block.CpeCount || i == Block.Air) return Block.Air;
 #endif
diff --git a/ClassicalSharp/Math/Physics/Searcher.cs b/ClassicalSharp/Math/Physics/Searcher.cs
index ccf0264ce..b13184a28 100644
--- a/ClassicalSharp/Math/Physics/Searcher.cs
+++ b/ClassicalSharp/Math/Physics/Searcher.cs
@@ -18,9 +18,13 @@ namespace ClassicalSharp.Physics {
 		
 		public State(int x, int y, int z, BlockID block, float tSquared) {
 			X = x << 3; Y = y << 3; Z = z << 3;
-			X |= (block & 0x07);
-			Y |= (block & 0x38) >> 3;
-			Z |= (block & 0xC0) >> 6;
+			X |= (block & 0x007);
+			Y |= (block & 0x038) >> 3;
+			#if !USE16_BIT
+			Z |= (block & 0x0C0) >> 6;
+			#else
+			Z |= (block & 0x1C0) >> 6;
+			#endif
 			this.tSquared = tSquared;
 		}
 	}
diff --git a/ClassicalSharp/MeshBuilder/Builder.cs b/ClassicalSharp/MeshBuilder/Builder.cs
index a7d0f348f..e89e91484 100644
--- a/ClassicalSharp/MeshBuilder/Builder.cs
+++ b/ClassicalSharp/MeshBuilder/Builder.cs
@@ -203,7 +203,7 @@ namespace ClassicalSharp {
 						X = x; Y = y; Z = z;
 						fullBright = BlockInfo.FullBright[b];
 						#if USE16_BIT
-						int tileIdx = b << 12;
+						int tileIdx = b << 10;
 						#else
 						int tileIdx = b << 8;
 						#endif
diff --git a/ClassicalSharp/Network/Protocols/Classic.cs b/ClassicalSharp/Network/Protocols/Classic.cs
index 3c5a4aecd..879e21a00 100644
--- a/ClassicalSharp/Network/Protocols/Classic.cs
+++ b/ClassicalSharp/Network/Protocols/Classic.cs
@@ -120,6 +120,9 @@ namespace ClassicalSharp.Network.Protocols {
 				if (mapSizeIndex == 4) {
 					if (map == null) {
 						int size = mapSize[0] << 24 | mapSize[1] << 16 | mapSize[2] << 8 | mapSize[3];
+						#if USE16_BIT
+						if (reader.ExtendedBlocks) size *= 2;
+						#endif
 						map = new byte[size];
 					}
 					mapIndex += gzipStream.Read(map, mapIndex, map.Length - mapIndex);
@@ -131,6 +134,14 @@ namespace ClassicalSharp.Network.Protocols {
 			game.WorldEvents.RaiseMapLoading(progress);
 		}
 		
+		#if USE16_BIT
+		static ushort[] UInt8sToUInt16s(byte[] src) {
+			ushort[] dst = new ushort[src.Length / 2];
+			Buffer.BlockCopy(src, 0, dst, 0, src.Length);
+			return dst;
+		}
+		#endif
+		
 		void HandleLevelFinalise() {
 			game.Gui.SetNewScreen(null);
 			game.Gui.activeScreen = prevScreen;
@@ -147,7 +158,11 @@ namespace ClassicalSharp.Network.Protocols {
 			Utils.LogDebug("map loading took: " + loadingMs);
 			
 			#if USE16_BIT
-			game.World.SetNewMap(Utils.UInt8sToUInt16s(map), mapWidth, mapHeight, mapLength);
+			if (reader.ExtendedBlocks) {
+				game.World.SetNewMap(UInt8sToUInt16s(map), mapWidth, mapHeight, mapLength);
+			} else{
+				game.World.SetNewMap(Utils.UInt8sToUInt16s(map), mapWidth, mapHeight, mapLength);
+			}
 			#else
 			game.World.SetNewMap(map, mapWidth, mapHeight, mapLength);
 			#endif
@@ -174,8 +189,8 @@ namespace ClassicalSharp.Network.Protocols {
 			byte id = reader.ReadUInt8();
 			string name = reader.ReadString();
 			string skin = name;
-			net.CheckName(id, ref name, ref skin);			
-			net.AddEntity(id, name, skin, true);			
+			net.CheckName(id, ref name, ref skin);
+			net.AddEntity(id, name, skin, true);
 			
 			if (!net.addEntityHack) return;
 			// Workaround for some servers that declare they support ExtPlayerList,
@@ -253,7 +268,7 @@ namespace ClassicalSharp.Network.Protocols {
 		}
 		
 		internal void ReadAbsoluteLocation(byte id, bool interpolate) {
-			Vector3 P = reader.ReadPosition(id);	
+			Vector3 P = reader.ReadPosition(id);
 			float rotY =  (float)Utils.PackedToDegrees(reader.ReadUInt8());
 			float headX = (float)Utils.PackedToDegrees(reader.ReadUInt8());
 			
@@ -267,7 +282,7 @@ namespace ClassicalSharp.Network.Protocols {
 		
 		internal void WriteChat(string text, bool partial) {
 			int payload = !net.SupportsPartialMessages ? EntityList.SelfID : (partial ? 1 : 0);
-			writer.WriteUInt8((byte)Opcode.Message);			
+			writer.WriteUInt8((byte)Opcode.Message);
 			writer.WriteUInt8((byte)payload);
 			writer.WriteString(text);
 		}