Error building J2EE modules

"duplicate entry: META-INF/ejb-jar.xml"

That's what IDEA spits out when I try to compile my project, which contains a couple of EJB modules, a WEB modules and some other normal modules.

All the EJB modules are organized like this:

i.e., the ejb-jar.xml lives inside the source directory. Maybe this is confusing IDEA? If this is the case, what could I do to prevent this (apart from moving the ejb-jar.xml, which I can't do)?