why checkbox text is appearing through android:text, is there any reason?

Checkbox text is not displaying through android:text.Tried by changing text color but the result is same. why this happening?

<CheckBox
        android:id="@+id/checkBoxMarkAsComplete"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:text="Mark as complete"
        android:textColor="@color/colorBlack"
        android:buttonTint="@color/colorVendorCheckBox"/>