diff --git a/smdev.c b/smdev.c
index b774908..0418b7d 100644
--- a/smdev.c
+++ b/smdev.c
@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <sys/ioctl.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 
 #include <linux/sockios.h>