diff --git a/src/platform.h b/src/platform.h
index 77a767875..d813fab9d 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -81,17 +81,12 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #endif /* _MSC_VER_ */
 
 #if defined __GNUC__
-# undef _BSD_SOURCE
-# define _BSD_SOURCE
+# undef _DEFAULT_SOURCE
+# define _DEFAULT_SOURCE
 # undef __USE_BSD
 # define __USE_BSD
 #endif
 
-#ifdef _BSD_SOURCE
-# undef __EXTENSIONS__
-# define __EXTENSIONS__
-#endif
-
 #ifdef SOLARIS
 # define _SYS_PROCSET_H
 #undef _XOPEN_SOURCE