Loading a module before and after adding a load path

[Diogo F. S. Ramos]

I have a module at `/path/to/foo'.

If I open a guile REPL and type:

(add-to-load-path "/path/to/foo")
(use-modules (foo bar))

everything works. But, if I type:

(use-modules (foo bar))
(add-to-load-path "/path/to/foo")
(use-modules (foo bar))

I get the same error I've got by using a module before adding the path:

ERROR: no code for module (foo bar)

How can I load a module if I tried loading it before adding the path?

I'm using Guile 2.0.5.