Actionbar in Dialog isn't working since Android Support Library v7, revision 22.1.0

Question

I have this AppCompatActivity with an actionbar which is presented as a dialog on tablets (sw600)

<style name="DialogTheme" parent="@style/Theme.AppCompat.Light.DialogWhenLarge">
</style>

This is working with Android Support Library v7, revision 22.0.+ but since 22.1.0 the actionbar isn't visible anymore. Only the title. It's working with a toolbar.

Any ideas how to make this work with a actionbar? Thx.