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 3bbf688b..0d745b91 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
@@ -66,6 +66,7 @@ import net.md_5.bungee.protocol.packet.Handshake;
 import net.md_5.bungee.protocol.packet.Kick;
 import net.md_5.bungee.protocol.packet.LegacyHandshake;
 import net.md_5.bungee.protocol.packet.LegacyPing;
+import net.md_5.bungee.protocol.packet.LoginAcknowledged;
 import net.md_5.bungee.protocol.packet.LoginPayloadResponse;
 import net.md_5.bungee.protocol.packet.LoginRequest;
 import net.md_5.bungee.protocol.packet.LoginSuccess;
@@ -690,6 +691,13 @@ public class InitialHandler extends PacketHandler implements PendingConnection
         disconnect( "Unexpected custom LoginPayloadResponse" );
     }
 
+    @Override
+    public void handle(LoginAcknowledged loginAcknowledged) throws Exception
+    {
+        // this packet should only be sent after the login success (it should be handled in the UpstreamBridge)
+        disconnect( "Unexpected LoginAcknowledged" );
+    }
+
     @Override
     public void handle(CookieResponse cookieResponse)
     {