diff --git a/libgphoto2_port/serial/unix.c b/libgphoto2_port/serial/unix.c
index 72b282200..3ad870bbe 100644
--- a/libgphoto2_port/serial/unix.c
+++ b/libgphoto2_port/serial/unix.c
@@ -76,10 +76,6 @@
 #  include <lockdev.h>
 #endif
 
-#ifndef O_NDELAY
-# define O_NDELAY 0
-#endif
-
 #include <gphoto2/gphoto2-port-result.h>
 #include <gphoto2/gphoto2-port-log.h>
 #include <gphoto2/gphoto2-port.h>