--- configure.ac.old	2013-05-12 21:21:48.541823071 +0100
+++ configure.ac.old	2013-05-12 21:22:36.838592347 +0100
@@ -27,7 +27,7 @@ 
 AC_CONFIG_HEADERS(config.h)
 AM_MAINTAINER_MODE
 
-SET_FEATURES="-D_ISOC99_SOURCE -D_POSIX_C_SOURCE=200112L"
+SET_FEATURES="-D_ISOC99_SOURCE -D_POSIX_C_SOURCE=200112L -D_BSD_SOURCE"
 
 case "${host_os}" in
   "")