diff --git a/demo/src/main/java/net/minestom/demo/Main.java b/demo/src/main/java/net/minestom/demo/Main.java
index f8ddbe0b6..6471f8564 100644
--- a/demo/src/main/java/net/minestom/demo/Main.java
+++ b/demo/src/main/java/net/minestom/demo/Main.java
@@ -12,6 +12,7 @@ import net.minestom.server.MinecraftServer;
 import net.minestom.server.command.CommandManager;
 import net.minestom.server.entity.Player;
 import net.minestom.server.event.server.ServerListPingEvent;
+import net.minestom.server.extras.MojangAuth;
 import net.minestom.server.extras.lan.OpenToLAN;
 import net.minestom.server.extras.lan.OpenToLANConfig;
 import net.minestom.server.instance.block.BlockManager;
@@ -138,7 +139,7 @@ public class Main {
 //        VelocityProxy.enable("abcdef");
         //BungeeCordProxy.enable();
 
-        //MojangAuth.init();
+        MojangAuth.init();
 
         // useful for testing - we don't need to worry about event calls so just set this to a long time
         OpenToLAN.open(new OpenToLANConfig().eventCallDelay(Duration.of(1, TimeUnit.DAY)));
diff --git a/src/main/java/net/minestom/server/network/ConnectionManager.java b/src/main/java/net/minestom/server/network/ConnectionManager.java
index 48508908f..aba084087 100644
--- a/src/main/java/net/minestom/server/network/ConnectionManager.java
+++ b/src/main/java/net/minestom/server/network/ConnectionManager.java
@@ -352,6 +352,7 @@ public final class ConnectionManager {
     @ApiStatus.Internal
     public void updateWaitingPlayers() {
         this.waitingPlayers.drain(player -> {
+            if (!player.isOnline()) return; // Player disconnected while in queued to join
             player.getPlayerConnection().setConnectionState(ConnectionState.PLAY);
             playPlayers.add(player);
             keepAlivePlayers.add(player);