diff --git a/config.project b/config.project
index c8c7c22..9dc959b 100644
--- a/config.project
+++ b/config.project
@@ -30,7 +30,7 @@ mb_ccenv_create_log=
 mb_ccenv_skip_native=
 
 # switches
-mb_default_cflags_common="-std=c99 -D_XOPEN_SOURCE=700"
+mb_default_cflags_common="-std=c99 -D_XOPEN_SOURCE=700 -D_BSD_SOURCE -D__BSD_VISIBLE"
 mb_default_cflags_common="$mb_default_cflags_common -I\$(SOURCE_DIR)/src/internal"
 mb_default_cflags_common="$mb_default_cflags_common -I\$(SOURCE_DIR)/include"
 mb_default_cflags_common="$mb_default_cflags_common -Ibuild"