Index: trunk/psLib/configure.in
===================================================================
--- trunk/psLib/configure.in	(revision 3191)
+++ trunk/psLib/configure.in	(revision 3199)
@@ -7,5 +7,12 @@
 
 dnl Setup CFLAGS with project-particulars
-CFLAGS="${CFLAGS=} -Wall -Werror -std=c99 -D_GNU_SOURCE"
+CFLAGS="${CFLAGS=} -std=c99"
+
+AH_VERBATIM([_GNU_SOURCE], 
+[/* Enable GNU extensions on systems that have them. */ 
+#ifndef _GNU_SOURCE 
+# define _GNU_SOURCE 
+#endif
+])
 
 AC_DISABLE_STATIC
@@ -123,4 +130,8 @@
 AC_SUBST(PERL_PREFIX,$PERL_PREFIX)
 
+dnl for MacOSX, check if sqrtf is in mx library.
+AC_CHECK_LIB(mx,sqrtf,
+  [PSLIB_LIBS="${PSLIB_LIBS=} -lmx"])
+
 dnl --------- set config/data file location --------------
 SYSCONFDIR=`cd $sysconfdir; pwd`
@@ -130,10 +141,9 @@
 AC_DEFINE_UNQUOTED(UTC_DAT_FILE, "$DATADIR/pslib/tai_utc.dat", [Location of the tai_utc.dat file])
 
-dnl for MacOSX, where sqrtf is in mx
-AC_CHECK_LIB(mx,sqrtf)
-
 DOXYGEN="doxygen Doxyfile"
 AC_CHECK_PROG(DOXYGEN,doxygen,[echo Doxygen not detected in configure stage.])
 AC_SUBST(DOXYGEN,$DOXYGEN)
+
+CFLAGS="${CFLAGS=} -Wall -Werror"
 
 dnl ---------------- export variables --------------------