On Fri, 7 Jul 2017, Marcin Błażejowski wrote: Well, 'FOO_func1', being public, can only have one definition, and loading FOO1.gfn has overwritten the definition given by FOO2.gfn. The long-standing behavior of gretl has been that a new function definition overrides any previous definition (except for private functions in packages). And in fact in this case, when gretl spotted the conflict between public packaged functions, it removed the entire package FOO2 from memory. (You might see on stderr, "unloading conflicting package <name>".) In some circumstances that _might_ be OK, but in the context you describe it's obviously not alright: the editor window for package FOO2 has become "orphaned" and is in a mixed-up state. I think the best solution to this is to protect a loaded package from having any of its public functions redefined "externally" (either by loading another package or by defining an unpackaged function with conflicting name). That's now in git. If you try the above again you should find that the loading of FOO1 is rejected: "The function FOO_func1 is already defined by package 'FOO2'" However, I'm not finished with checking the consequences of this change; I'll do some testing and check for fall-out. Allin