Android: setting fontFamily to TextAppearance not working

I wanted to have a standard TextStyle header with fonts, and every inherited style (HeaderStyle, HeaderTwoStyle) should be able to display the correct font if I wanted to override the font in the Headline. But its not working ...

<style name="Headline1" parent="TextAppearance.AppCompat.Headline">
    <item name="android:textSize">@dimen/font_28sp</item>
    <item name="android:fontFamily">sans-serif</item>
    <item name="android:textColor">@color/headline1</item>
</style>

<style name="HeaderStyle">
    <item name="android:layout_gravity">center_horizontal</item>
    <item name="android:gravity">center</item>
    <item name="android:textAppearance">@style/Headline1</item>
</style>

<style name="HeaderTwoStyle">
    <item name="android:layout_gravity">center_horizontal</item>
    <item name="android:gravity">center</item>
    <item name="android:textAppearance">@style/Headline1</item>
</style>