std.signal woes :/

[Damian]

Ok signals work fine, until I use them in a descendant class.

Snippet:
-----------------
import std.signals;

class ClassA
{
	public mixin Signal!(int) addNumber1;
}

class ClassB : ClassA
{
	public mixin Signal!(int) addNumber2;
}

Error:
\dmd2\src\phobos\std\signals.d(0,0): Error: function 
main.ClassB.Signal!(int).emit cannot override final function 
main.ClassA.Signal!(int).emit (moooo)


Is this expected behavior or a bug in my code?