diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/ProtocolConstants.java b/protocol/src/main/java/net/md_5/bungee/protocol/ProtocolConstants.java
index b53b1e50ff..9028dc1303 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/ProtocolConstants.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/ProtocolConstants.java
@@ -47,7 +47,7 @@ public class ProtocolConstants
     public static final int MINECRAFT_1_20_3 = 765;
     public static final int MINECRAFT_1_20_5 = 766;
     public static final int MINECRAFT_1_21 = 767;
-    public static final int MINECRAFT_1_21_2 = 1073742032;
+    public static final int MINECRAFT_1_21_2 = 1073742034;
     public static final List<String> SUPPORTED_VERSIONS;
     public static final List<Integer> SUPPORTED_VERSION_IDS;
 
diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/packet/LoginSuccess.java b/protocol/src/main/java/net/md_5/bungee/protocol/packet/LoginSuccess.java
index 60ff5700c9..daa6d18306 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/packet/LoginSuccess.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/packet/LoginSuccess.java
@@ -37,7 +37,7 @@ public void read(ByteBuf buf, ProtocolConstants.Direction direction, int protoco
         {
             properties = readProperties( buf );
         }
-        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 && protocolVersion < ProtocolConstants.MINECRAFT_1_21_2 )
         {
             // Whether the client should disconnect on its own if it receives invalid data from the server
             buf.readBoolean();
@@ -59,7 +59,7 @@ public void write(ByteBuf buf, ProtocolConstants.Direction direction, int protoc
         {
             writeProperties( properties, buf );
         }
-        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 )
+        if ( protocolVersion >= ProtocolConstants.MINECRAFT_1_20_5 && protocolVersion < ProtocolConstants.MINECRAFT_1_21_2 )
         {
             // Whether the client should disconnect on its own if it receives invalid data from the server
             // Vanilla sends true so we also send true
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
index 091ae9a226..224f231b63 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
@@ -196,6 +196,7 @@ public void handle(PluginMessage pluginMessage) throws Exception
     @Override
     public void handle(LegacyHandshake legacyHandshake) throws Exception
     {
+        Preconditions.checkState( !this.legacy, "Not expecting LegacyHandshake" );
         this.legacy = true;
         ch.close( bungee.getTranslation( "outdated_client", bungee.getGameVersion() ) );
     }
@@ -203,6 +204,7 @@ public void handle(LegacyHandshake legacyHandshake) throws Exception
     @Override
     public void handle(LegacyPing ping) throws Exception
     {
+        Preconditions.checkState( !this.legacy, "Not expecting LegacyPing" );
         this.legacy = true;
         final boolean v1_5 = ping.isV1_5();
 
@@ -342,7 +344,7 @@ public void handle(PingPacket ping) throws Exception
     @Override
     public void handle(Handshake handshake) throws Exception
     {
-        Preconditions.checkState( thisState == State.HANDSHAKE, "Not expecting HANDSHAKE" );
+        Preconditions.checkState( thisState == State.HANDSHAKE && !this.legacy, "Not expecting HANDSHAKE" );
         this.handshake = handshake;
         ch.setVersion( handshake.getProtocolVersion() );
         ch.getHandle().pipeline().remove( PipelineUtils.LEGACY_KICKER );
@@ -420,7 +422,7 @@ public void handle(Handshake handshake) throws Exception
     @Override
     public void handle(LoginRequest loginRequest) throws Exception
     {
-        Preconditions.checkState( thisState == State.USERNAME, "Not expecting USERNAME" );
+        Preconditions.checkState( thisState == State.USERNAME && this.loginRequest == null, "Not expecting USERNAME" );
 
         if ( !AllowedCharacters.isValidName( loginRequest.getData(), onlineMode ) )
         {