Xamarin.Forms 1.3 Behavior.BindingContext is null

Hi all!

I have this XAML:

        <Entry Keyboard="Numeric" Text="{Binding Pin, Mode=TwoWay}" IsVisible="{Binding ShowLogin}">
          <Entry.Behaviors>
            <controls:FocusBehavior Focused="{Binding PinFocused, Mode=TwoWay}" />
          </Entry.Behaviors>
        </Entry>

Problem is that Entry has BindingContext and FocusBehavior has no BindingContext or InheritedBindingContext. Why? Should I set BindingContext manually? Why?
Thank you!