Hi, While trying to compile filesystem under HPUX because the WCHAR_MAX define value used was including a ')' character (because the value has a cast). The include file wchar.h defines the correct WCHAR_MAX if macro _INCLUDE_STDC__SOURCE_199901 is defined. I then solved the problem by changing the filesystem's Jamfile.v2 to add the lines: : requirements <host-os>hpux,<toolset>gcc:<define>_INCLUDE_STDC__SOURCE_199901 Don't know however if this is the best way to solve the issue... Thanks, Rui