Configuring a JAAS PropertyLoginModule using karaf.home system property does not work on Windows

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
        xmlns:ext="http://aries.apache.org/blueprint/xmlns/blueprint-ext/v1.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:jaas="http://karaf.apache.org/xmlns/jaas/v1.0.0"
        xsi:schemaLocation="
       http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd">

    <ext:property-placeholder placeholder-prefix="$[" placeholder-suffix="]"/>

    <jaas:config name="test" rank="1">
        <jaas:module className="org.apache.karaf.jaas.modules.properties.PropertiesLoginModule"
                     flags="required">
            users = $[karaf.home]/etc/testuser.properties
        </jaas:module>
    </jaas:config>
</blueprint>