--- a/configure.in
+++ b/configure.in
@@ -68,7 +68,7 @@
 case $my_build_os in
 	aix*)		AC_DEFINE(AIX_STRANGENESS, 1, [ defined on AIX systems. ]) ;;
 	osf1*)		AC_DEFINE(TRU64_STRANGENESS, 1, [ defined on OSF systems. ]) ;;
-	linux*)		AC_DEFINE(_BSD_SOURCE, 1, [ defined usually on linux systems ] ) ;;
+	linux*)		AC_DEFINE(_DEFAULT_SOURCE, 1, [ defined usually on linux systems ] ) ;;
 	gnu/kfreebsd*)		AC_DEFINE(_BSD_SOURCE, 1, [ defined usually on debian kfreebsd systems ] ) ;;
 	bsd/os*)	;;
 	freebsd*)	;;