[1.7.10] How to make commands registered in a mod accessible to regular players?

I've tried overriding the getRequiredPermissionLevel() method to return 0, but only operators are still able to use this command.

The code is as follows:

public class CommandTest extends CommandBase {

public String getCommandName() { return "test"; }

public String getCommandUsage(ICommandSender p_71518_1_) { return null; }

 public void processCommand(ICommandSender p_71515_1_, String[] p_71515_2_) { p_71515_1_.addChatMessage(new ChatComponentText("abc")); }

 public int getRequiredPermissionLevel(){ return 0; } }

public class start {

 public static final String MODID = "register"; public static final String VERSION = "1.0";

@EventHandler public void init(FMLInitializationEvent event) { }

@EventHandler public void serverStarting(FMLServerStartingEvent event) { event.registerServerCommand(new CommandTest()); } }

thanks to everybody