md-select options still visible when closing md-dialog

Question

I have a md-dialog with two md-select directives in it. When I hit the md-select then close the dialog, the options are still visible..

I searched on google and github but I can't find any information on this behaviour.

Here's a screenshot to illustrate what I mean :

And that's what happen when I click on cancel :

I'm using angular material V1.1.1