Rectangle's corner border radius is not perfect (Android Shape)

I tried to create a rectangle shape with corner radius and border on android. I almost made it, just a little problem that i cant solve until now :

The border already has some radius on its corner, but the inner rectangle does NOT (please see the red mark on the image).

This is my code :

<shape xmlns:android="http://ift.tt/nIICcg" android:shape="rectangle">
    <corners android:radius="10dp"/>
    <stroke  android:width="3dp" android:color="#000000" />
</shape>

I use this shape by using android:src on the ImageView.

This is how i use the shape :

<ImageView
        android:src="@drawable/rectangle"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

Please kindly help me out, Thanks.