List of all "buitin" modules in utop, to avoid name collision

A few minutes ago, I noticed that utop has a builtin Absolute_path module.
My homemade OCaml library also had a module with the exact same name, so I had to rename it to be able to use it inside utop.
Is there a way to get a list of all module names already in use inside utop, to avoid other name collisions ?

Any help appreciated.