diff --git a/src/net/minecraft/network/packets/Packet51MapChunk.java b/src/net/minecraft/network/packets/Packet51MapChunk.java
index 942b3db..05f0d6c 100644
--- a/src/net/minecraft/network/packets/Packet51MapChunk.java
+++ b/src/net/minecraft/network/packets/Packet51MapChunk.java
@@ -3,11 +3,12 @@ package net.minecraft.network.packets;
 import net.minecraft.network.NetHandler;
 import net.minecraft.world.World;
 
+import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.util.zip.DataFormatException;
-import java.util.zip.Deflater;
+import java.util.zip.DeflaterOutputStream;
 import java.util.zip.Inflater;
 
 public class Packet51MapChunk extends Packet {
@@ -19,6 +20,9 @@ public class Packet51MapChunk extends Packet {
     public int zSize;
     public byte[] chunk;
     private int chunkSize;
+    // Patch start
+    public byte[] uncompressedChunk;
+    // Patch end
 
     public Packet51MapChunk() {
         this.isChunkDataPacket = true;
@@ -32,17 +36,20 @@ public class Packet51MapChunk extends Packet {
         this.xSize = var4;
         this.ySize = var5;
         this.zSize = var6;
-        byte[] var8 = var7.getChunkData(var1, var2, var3, var4, var5, var6);
-        Deflater var9 = new Deflater(-1);
+        // Patch start
+        //byte[] var8 = var7.getChunkData(var1, var2, var3, var4, var5, var6);
+        //Deflater var9 = new Deflater(-1);
 
-        try {
-            var9.setInput(var8);
-            var9.finish();
-            this.chunk = new byte[var4 * var5 * var6 * 5 / 2];
-            this.chunkSize = var9.deflate(this.chunk);
-        } finally {
-            var9.end();
-        }
+        //try {
+        //    var9.setInput(var8);
+        //    var9.finish();
+        //    this.chunk = new byte[var4 * var5 * var6 * 5 / 2];
+        //    this.chunkSize = var9.deflate(this.chunk);
+        //} finally {
+        //    var9.end();
+        //}
+        this.uncompressedChunk = var7.getChunkData(var1, var2, var3, var4, var5, var6);
+        // Patch end
 
     }
 
@@ -71,6 +78,15 @@ public class Packet51MapChunk extends Packet {
     }
 
     public void writePacketData(DataOutputStream var1) throws IOException {
+        // Patch start
+        ByteArrayOutputStream compressed = new ByteArrayOutputStream();
+        try (DeflaterOutputStream dos = new DeflaterOutputStream(compressed)) {
+            dos.write(this.uncompressedChunk);
+        } catch (IOException ignore) {
+        }
+        this.chunk = compressed.toByteArray();
+        this.chunkSize = this.chunk.length;
+        // Patch end
         var1.writeInt(this.xPosition);
         var1.writeShort(this.yPosition);
         var1.writeInt(this.zPosition);