diff --git a/server/drivers/mtc_s16209x.c b/server/drivers/mtc_s16209x.c
index 55e48e7..fda30f8 100644
--- a/server/drivers/mtc_s16209x.c
+++ b/server/drivers/mtc_s16209x.c
@@ -49,6 +49,7 @@
 #include <fcntl.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/file.h>
 
 #ifdef HAVE_CONFIG_H
 # include "config.h"