diff --git a/rtl/unix/cwstring.pp b/rtl/unix/cwstring.pp
index 276d5437d4..e686ee4506 100644
--- a/rtl/unix/cwstring.pp
+++ b/rtl/unix/cwstring.pp
@@ -58,27 +58,32 @@ function towlower(__wc:wint_t):wint_t;cdecl;external libiconvname name 'towlower
 function towupper(__wc:wint_t):wint_t;cdecl;external libiconvname name 'towupper';
 function wcscoll (__s1:pwchar_t; __s2:pwchar_t):cint;cdecl;external libiconvname name 'wcscoll';
 function strcoll (__s1:pchar; __s2:pchar):cint;cdecl;external libiconvname name 'strcoll';
+function setlocale(category: cint; locale: pchar): pchar; cdecl; external clib name 'setlocale';
 
 const
 {$ifdef linux}
   __LC_CTYPE = 0;
+  LC_ALL = 6;
   _NL_CTYPE_CLASS = (__LC_CTYPE shl 16);
   _NL_CTYPE_CODESET_NAME = (_NL_CTYPE_CLASS)+14;
   CODESET = _NL_CTYPE_CODESET_NAME;
 {$else linux}
 {$ifdef darwin}
   CODESET = 0;
+  LC_ALL = 0;
 {$else darwin}
 {$ifdef FreeBSD} // actually FreeBSD5. internationalisation is afaik not default on 4.
   __LC_CTYPE = 0;
+  LC_ALL = 0;
   _NL_CTYPE_CLASS = (__LC_CTYPE shl 16);
   _NL_CTYPE_CODESET_NAME = (_NL_CTYPE_CLASS)+14;
   CODESET = 0; // _NL_CTYPE_CODESET_NAME;
 {$else freebsd}
 {$ifdef solaris}
   CODESET=49;
+  LC_ALL = 6;
 {$else}
-{$error lookup the value of CODESET in /usr/include/langinfo.h for your OS }
+{$error lookup the value of CODESET in /usr/include/langinfo.h, and the value of LC_ALL in /usr/include/locale.h for your OS }
 // and while doing it, check if iconv is in libc, and if the symbols are prefixed with iconv_ or libiconv_
 {$endif solaris}
 {$endif FreeBSD}
@@ -372,18 +377,17 @@ end;
 initialization
   SetCWideStringManager;
   initcriticalsection(iconv_lock);
+
+  { you have to call setlocale(LC_ALL,'') to initialise the langinfo stuff  }
+  { with the information from the environment variables according to POSIX  }
+  { (some OSes do this automatically, but e.g. Darwin and Solaris don't)    }
+  setlocale(LC_ALL,'');
+
   { init conversion tables }
-{$if not defined(darwin) and not defined(solaris)}
   iconv_wide2ansi:=iconv_open(nl_langinfo(CODESET),unicode_encoding);
   iconv_ansi2wide:=iconv_open(unicode_encoding,nl_langinfo(CODESET));
   iconv_ucs42ansi:=iconv_open(nl_langinfo(CODESET),'UCS4');
   iconv_ansi2ucs4:=iconv_open('UCS4',nl_langinfo(CODESET));
-{$else darwin or solaris}
-  iconv_wide2ansi:=iconv_open('UTF-8',unicode_encoding);
-  iconv_ansi2wide:=iconv_open(unicode_encoding,'UTF-8');
-  iconv_ucs42ansi:=iconv_open('UTF-8','UCS4');
-  iconv_ansi2ucs4:=iconv_open('UCS4','UTF-8');
-{$endif darwin or solaris}
 finalization
   donecriticalsection(iconv_lock);
   iconv_close(iconv_ansi2wide);