React Native 0.20 border radius problem

index.ios.js

import React, {
    StyleSheet,
    View,
    AppRegistry,
} from 'react-native';

const BorderRadiusProblem = () => {
    const styles = StyleSheet.create({
        wrapper: {
            padding: 16,
            paddingTop: 40,
            backgroundColor: 'purple',
        },
        button: {
            flex: 1,
            borderColor: 'white',
            borderWidth: 2,
            padding: 8,
            borderRadius: 10,
            borderTopRightRadius: 0,
            borderBottomRightRadius: 0,
        }
    });

    return (
        <View style={styles.wrapper}>
            <View style={styles.button}/>
        </View>
    );
};


AppRegistry.registerComponent('BorderRadiusProblem', () => BorderRadiusProblem);