Names of const global variables (i.e. generated macroses for them) interfere with function params and async closure members

See attached files
if I declare global string variable like this:
    const string some_str = "hello world";
vala generates preprocessor macros:
    #define some_str "hello world"
(see line 30 in main.c)
which interferes with generated param in
    void method_async (const gchar* some_str, GAsyncReadyCallback _callback_, gpointer _user_data_) {
(see line 57 in main.c)
and closure members
    _data_->some_str
(see lines 52, 66, 86 in main.c)