fontFamily param seems to be ignored

Question

I'm facing very strange problem here:

I have EditText:

<EditText
    android:layout_width="230dp"
    android:layout_height="wrap_content"
    android:id="@+id/editLogin"
    android:layout_gravity="center_horizontal|top"
    android:hint="@string/login_hint"
    android:inputType="textEmailAddress"
    android:fontFamily="sans-serif-light"           
    android:layout_marginTop="200dp"/>

as you see, there's fontFamily = sans-serif-light but when I install this build on device or emulator I got roboto normal font.

Where am I wrong?