completion-at-point in evil mode error

Question

Why do I get the error:

Symbol's function definition is void: completion-at-point

When I type :e (in evil mode), then use tab-completion to complete a file name, while using emacs 23 on windows.

I don't seem to get this error on linux, however I would like to have it working in windows as well.

My configuration is available at https://github.com/arafangion/emacs.d