I two modules in same src folder. mod1 declares function I wish to use in module mod2: -module(mod1). -export([myfunc/1]). myfunc(A) -> {ok}. In other module I not import mod1: -module(mod2). If I do "mod1:" in mod2 it recognizes "myfunc", problem is at run-time when I call mod1:myfunc(A) I get "undefined function mod1:myfunc/1" I not understand why I get error if intellisense detect my mod1 function in mod2?