E_STRICT on inheritance + method parameter defaults?

Hello all, This crept up as the result of a bug report (not mine -- http://bugs.php.net/34494), and a small discussion on IRC: Why does an E_STRICT get raised when extending a class, and altering the method's proto defaults? I understand why it would be thrown when adding/changing parameters, but why when simply changing $foo to $foo=1 ? Honest question -- I'm not trying to change the behavior, here. It doesn't seem "correct" to me, but I look forward to an explanation that I've simply overlooked. S