Additional webResources are not added to the component list when using WTP projects generation

I have a war project, with the standard layout :
+ project
+ src
+ main
+ java
+ resources
+ webapp
But my project is also relying on a common web application framework, containing web resources I must add to my project.
So in the pom.xml, for the maven-war-plugin configuration, I have additional webResources declared :
<plugin>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<webResources>
<webResource>
<directory>${project.build.directory}/fwk</directory>
<webResource>
</webResources>
</configuration>
</plugin>

When I generate the eclipse project, with WTP activated, the .component generated does not include the wb-resource element corresponding to my webResource. It should contain :
<wb-resource deploy-path="/" source-path="target/fwk"/>