Fluido Skin for Maven Site: Doxia Problem

Question

I am trying to use the Fluido Skin for my Maven Site, but get the error:

Cannot use skin: has 1.8 Doxia Sitetools prerequisite, but current is 1.7.4

My site.xml contains the skin

<skin>
  <groupId>org.apache.maven.skins</groupId>
  <artifactId>maven-fluido-skin</artifactId>
  <version>1.7</version>
</skin>

and my pom contains:

  <plugin>
    <artifactId>maven-site-plugin</artifactId>
    <version>3.6</version>
    <dependencies>
      <dependency>
        <groupId>org.apache.maven.wagon</groupId>
        <artifactId>wagon-webdav-jackrabbit</artifactId>
        <version>3.3.1</version>
      </dependency>
      <dependency>
        <groupId>org.apache.maven.doxia</groupId>
        <artifactId>doxia-module-xhtml</artifactId>
        <version>1.8</version>
      </dependency>
    </dependencies>
  </plugin>

With maven-fluido-skin in version 1.6 everything works fine.

I do not know where/how I need to upgrade doxia. Can somebody guide me?