Schema tool fail to handle ManyToMany relation with an existing joinTable

The schemaTool fail with a Doctrine\DBAL\Schema\SchemaException when trying to handle ManyToMany relation with an existing joinTable.

My use case :

I'm using the Tree DoctrineExtension with the Closure strategy. It create a mapping between my Category entity and a CategoryClosure entity.

For conveniency, I've setup a ManyToMany relation between Category and Category with the CategoryClosure table as joinTable.

Doctrine ORM handle perfectly this case but the schema tool is failing with :
The table with name 'category_closure' already exists.