diff --git a/legacyforge/build.gradle b/legacyforge/build.gradle
index c968766..b24fa4c 100644
--- a/legacyforge/build.gradle
+++ b/legacyforge/build.gradle
@@ -6,6 +6,7 @@ dependencies {
 jar {
     exclude("cpw/mods/fml/relauncher/FMLInjectionData.class")
     exclude("net/minecraftforge/fml/relauncher/FMLInjectionData.class")
+    exclude("cpw/mods/fml/relauncher/IClassTransformer.class")
 
     manifest {
         attributes([
diff --git a/legacyforge/src/main/java/cpw/mods/fml/relauncher/IClassTransformer.java b/legacyforge/src/main/java/cpw/mods/fml/relauncher/IClassTransformer.java
new file mode 100644
index 0000000..78e1086
--- /dev/null
+++ b/legacyforge/src/main/java/cpw/mods/fml/relauncher/IClassTransformer.java
@@ -0,0 +1,21 @@
+/*
+ * The FML Forge Mod Loader suite.
+ * Copyright (C) 2012 cpw
+ *
+ * This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+package cpw.mods.fml.relauncher;
+
+public interface IClassTransformer
+{
+    public byte[] transform(String name, byte[] bytes); // 1.4
+    public byte[] transform(String name, String transformedName, byte[] bytes); // 1.5
+}
diff --git a/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformer.java b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerLaunchwrapper.java
similarity index 85%
rename from legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformer.java
rename to legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerLaunchwrapper.java
index 477d453..38606ff 100644
--- a/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformer.java
+++ b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerLaunchwrapper.java
@@ -3,7 +3,7 @@
 import io.dogboy.serializationisbad.core.Patches;
 import net.minecraft.launchwrapper.IClassTransformer;
 
-public class SIBTransformer implements IClassTransformer {
+public class SIBTransformerLaunchwrapper implements IClassTransformer {
     @Override
     public byte[] transform(String name, String transformedName, byte[] basicClass) {
         if (Patches.getPatchModuleForClass(transformedName) == null) return basicClass;
diff --git a/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerRelauncher.java b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerRelauncher.java
new file mode 100644
index 0000000..a49cd5e
--- /dev/null
+++ b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SIBTransformerRelauncher.java
@@ -0,0 +1,18 @@
+package io.dogboy.serializationisbad.legacyforge;
+
+import cpw.mods.fml.relauncher.IClassTransformer;
+import io.dogboy.serializationisbad.core.Patches;
+
+public class SIBTransformerRelauncher implements IClassTransformer {
+    @Override
+    public byte[] transform(String name, byte[] bytes) {
+        return this.transform(null, name, bytes);
+    }
+
+    @Override
+    public byte[] transform(String name, String transformedName, byte[] bytes) {
+        if (Patches.getPatchModuleForClass(transformedName) == null) return bytes;
+
+        return Patches.patchClass(bytes, transformedName, false);
+    }
+}
diff --git a/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SerializationIsBadCoreMod.java b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SerializationIsBadCoreMod.java
index a6b3a4d..7432aec 100644
--- a/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SerializationIsBadCoreMod.java
+++ b/legacyforge/src/main/java/io/dogboy/serializationisbad/legacyforge/SerializationIsBadCoreMod.java
@@ -19,11 +19,23 @@ public SerializationIsBadCoreMod() {
         SerializationIsBad.init(minecraftHome);
     }
 
+    @Override
+    public String[] getLibraryRequestClass() {
+        return new String[0];
+    }
+
     @Override
     public String[] getASMTransformerClass() {
         if (SerializationIsBad.isAgentActive()) return new String[0];
 
-        return new String[]{ SIBTransformer.class.getCanonicalName() };
+        // Check if we're in Forge Relauncher era (pre 1.6)
+        try {
+            Class.forName("cpw.mods.fml.relauncher.IClassTransformer");
+            return new String[] { SIBTransformerRelauncher.class.getCanonicalName() };
+        } catch (ClassNotFoundException ignored) {}
+
+        // Launchwrapper / LegacyLauncher
+        return new String[]{ SIBTransformerLaunchwrapper.class.getCanonicalName() };
     }
 
     @Override
diff --git a/legacyforge/src/main/java/net/minecraftforge/fml/relauncher/IFMLLoadingPlugin.java b/legacyforge/src/main/java/net/minecraftforge/fml/relauncher/IFMLLoadingPlugin.java
index 69bfb62..0caf9e2 100644
--- a/legacyforge/src/main/java/net/minecraftforge/fml/relauncher/IFMLLoadingPlugin.java
+++ b/legacyforge/src/main/java/net/minecraftforge/fml/relauncher/IFMLLoadingPlugin.java
@@ -34,6 +34,13 @@
  */
 public interface IFMLLoadingPlugin
 {
+    /**
+     * Return a list of classes that implement the ILibrarySet interface
+     *
+     * @return a list of classes that implement the ILibrarySet interface
+     */
+    String[] getLibraryRequestClass();
+
     /**
      * Return a list of classes that implements the IClassTransformer interface
      * @return a list of classes that implements the IClassTransformer interface
diff --git a/serializationisbad.json b/serializationisbad.json
index eaaf930..1a0d1ac 100644
--- a/serializationisbad.json
+++ b/serializationisbad.json
@@ -253,9 +253,12 @@
                 "logisticspipes.network.packets.debuggui.DebugInfoUpdate",
                 "logisticspipes.network.packets.debuggui.DebugTargetResponse",
                 "logisticspipes.network.packets.debuggui.DebugTypePacket",
-                "logisticspipes.network.packets.routingdebug.RoutingUpdateTargetResponse"
+                "logisticspipes.network.packets.routingdebug.RoutingUpdateTargetResponse",
+                "logisticspipes.network.packets.GuiArgumentPacket"
+            ],
+            "classAllowlist": [
+                "I"
             ],
-            "classAllowlist": [],
             "packageAllowlist": [
                 "logisticspipes"
             ]
@@ -368,6 +371,17 @@
             "packageAllowlist": [
                 "com.possible_triangle.brazier"
             ]
+        },
+        {
+            "classesToPatch": [
+                "com.thevoxelbox.voxelpacket.common.encoders.VoxelPacketEncoderObject"
+            ],
+            "classAllowlist": [],
+            "packageAllowlist": [
+                "com.thevoxelbox.voxelmap",
+                "com.thevoxelbox.voxelpacket",
+                "com.thevoxelbox.voxelplayer"
+            ]
         }
     ],
     "classAllowlist": [