diff --git a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java
index 714c0944d..0615bb726 100644
--- a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java
+++ b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java
@@ -5,13 +5,12 @@ import com.google.common.collect.HashBiMap;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
-import io.netty.util.collection.IntObjectHashMap;
-import io.netty.util.collection.IntObjectMap;
 import us.myles.ViaVersion.util.GsonUtil;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -30,13 +29,7 @@ public class MappingData {
 
         // TODO: Remove how verbose this is
         System.out.println("Loading block mapping...");
-        try {
-            Class.forName("io.netty.util.collection.IntObjectMap");
-            blockMappings = new BMNettyCollections();
-        } catch (ClassNotFoundException e) {
-            blockMappings = new BMJDKCollections();
-        }
-        blockMappings.init(mapping1_12, mapping1_13);
+        blockMappings = new BlockMappingsShortArray(mapping1_12, mapping1_13);
         System.out.println("Loading item mapping...");
         mapIdentifiers(oldToNewItems, mapping1_12.getAsJsonObject("items"), mapping1_13.getAsJsonObject("items"));
         System.out.println("Loading new tags...");
@@ -124,47 +117,32 @@ public class MappingData {
         }
     }
 
-    public interface BlockMappings {
-        void init(JsonObject mapping1_12, JsonObject mapping1_13);
-        Integer getNewBlock(int old);
-    }
-
-    private static class BMJDKCollections implements BlockMappings {
-        private Map<Integer, Integer> oldToNew = new HashMap<>();
-
-        @Override
-        public void init(JsonObject mapping1_12, JsonObject mapping1_13) {
-            mapIdentifiers(oldToNew, mapping1_12.getAsJsonObject("blocks"), mapping1_13.getAsJsonObject("blocks"));
-        }
-
-        @Override
-        public Integer getNewBlock(int old) {
-            return oldToNew.get(old);
-        }
-    }
-
-    private static class BMNettyCollections implements BlockMappings {
-        private IntObjectMap<Integer> oldToNew = new IntObjectHashMap<>();
-
-        @Override
-        public void init(JsonObject mapping1_12, JsonObject mapping1_13) {
-            mapIdentifiers(oldToNew, mapping1_12.getAsJsonObject("blocks"), mapping1_13.getAsJsonObject("blocks"));
-        }
-
-        @Override
-        public Integer getNewBlock(int old) {
-            return oldToNew.get(old);
-        }
-
-        private static void mapIdentifiers(IntObjectMap<Integer> output, JsonObject oldIdentifiers, JsonObject newIdentifiers) {
-            for (Map.Entry<String, JsonElement> entry : oldIdentifiers.entrySet()) {
-                Map.Entry<String, JsonElement> value = findValue(newIdentifiers, entry.getValue().getAsString());
-                if (value == null) {
-                    System.out.println("No key for " + entry.getValue() + " :( ");
-                    continue;
-                }
-                output.put(Integer.parseInt(entry.getKey()), Integer.parseInt(value.getKey()));
+    private static void mapIdentifiers(short[] output, JsonObject oldIdentifiers, JsonObject newIdentifiers) {
+        for (Map.Entry<String, JsonElement> entry : oldIdentifiers.entrySet()) {
+            Map.Entry<String, JsonElement> value = findValue(newIdentifiers, entry.getValue().getAsString());
+            if (value == null) {
+                System.out.println("No key for " + entry.getValue() + " :( ");
+                continue;
             }
+            output[Integer.parseInt(entry.getKey())] = Short.parseShort(value.getKey());
+        }
+    }
+
+    public interface BlockMappings {
+        short getNewBlock(int old);
+    }
+
+    private static class BlockMappingsShortArray implements BlockMappings {
+        private short[] oldToNew = new short[4084];
+
+        private BlockMappingsShortArray(JsonObject mapping1_12, JsonObject mapping1_13) {
+            Arrays.fill(oldToNew, (short) -1);
+            mapIdentifiers(oldToNew, mapping1_12.getAsJsonObject("blocks"), mapping1_13.getAsJsonObject("blocks"));
+        }
+
+        @Override
+        public short getNewBlock(int old) {
+            return old >= 0 && old < oldToNew.length ? oldToNew[old] : -1;
         }
     }
 }
diff --git a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/WorldPackets.java b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/WorldPackets.java
index 0920d1d14..10fcd78c8 100644
--- a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/WorldPackets.java
+++ b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/WorldPackets.java
@@ -339,12 +339,12 @@ public class WorldPackets {
     }
 
     public static int toNewId(int oldId) {
-        Integer newId = MappingData.blockMappings.getNewBlock(oldId);
-        if (newId != null) {
+        short newId = MappingData.blockMappings.getNewBlock(oldId);
+        if (newId != -1) {
             return newId;
         }
         newId = MappingData.blockMappings.getNewBlock(oldId & ~0xF); // Remove data
-        if (newId != null) {
+        if (newId != -1) {
             System.out.println("Missing block " + oldId);
             return newId;
         }
diff --git a/pom.xml b/pom.xml
index 98aaa200e..009961095 100644
--- a/pom.xml
+++ b/pom.xml
@@ -95,12 +95,10 @@
         </dependency>
 
         <!-- Netty (Network Library) -->
-        <!-- You should make this work with 4.0.20.Final -->
-        <!-- Using 4.0.23.Final to use Netty Collections -->
         <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-all</artifactId>
-            <version>4.0.23.Final</version>
+            <version>4.0.20.Final</version>
             <scope>provided</scope>
             <optional>true</optional>
         </dependency>