diff --git a/camlibs/ptp2/ptpip.c b/camlibs/ptp2/ptpip.c
index f519ead53..f09bf57a5 100644
--- a/camlibs/ptp2/ptpip.c
+++ b/camlibs/ptp2/ptpip.c
@@ -28,7 +28,7 @@
  *
  * Nikon WU-1* adapters might use 0011223344556677 as GUID always...
  */
-#define _BSD_SOURCE
+#define _DEFAULT_SOURCE
 #include "config.h"
 
 #include <stdlib.h>
diff --git a/camlibs/ptp2/usb.c b/camlibs/ptp2/usb.c
index 02f7fe68c..0630ede43 100644
--- a/camlibs/ptp2/usb.c
+++ b/camlibs/ptp2/usb.c
@@ -20,7 +20,7 @@
  * Boston, MA  02110-1301  USA
  */
 
-#define _BSD_SOURCE
+#define _DEFAULT_SOURCE
 #include <config.h>
 #include "ptp.h"
 #include "ptp-private.h"