Hi, newlib's stdlib.h declares int putenv( const char* ); According to SUSv3, Linux and Solaris, this should be (without const) int putenv( char* ); FreeBSD, however has the same declaration as newlib (with const). At least I am in favor of following SUSv3 and to ignore BSD's behaviour, i.e. I vote for changing newlib's putenv to match with SUSv3. Ralf