How to control boolean rendering in xslt

To conform with the <boolean> spec of Xml-RPC I need to transform my xs:boolean from true|false to 1|0.

I solved this using xsl:choose

<xsl:template match="Foo">
    <member>
        <name>Baz</name>
        <value>
            <boolean>
                <xsl:choose>
                    <xsl:when test=".='true'">1</xsl:when>
                    <xsl:otherwise>0</xsl:otherwise>
                </xsl:choose>
            </boolean>
        </value>
    </member>
</xsl:template>

but was wondering if there is a less brittle way of controlling how boolean values are rendered when transformed with xslt 1.0.