diff --git a/config.project b/config.project
index bef65ae..50fa4c2 100644
--- a/config.project
+++ b/config.project
@@ -42,7 +42,7 @@ mb_hosted=
 mb_freestanding=
 
 # switches
-mb_default_cflags_common="\$(_CFLAGS_std_c99) -D_XOPEN_SOURCE=700 -D_BSD_SOURCE -D__BSD_VISIBLE"
+mb_default_cflags_common="\$(_CFLAGS_std_c99) -D_XOPEN_SOURCE=700 -D_DEFAULT_SOURCE"
 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"