diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 185bfe933..9ee553ea8 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -32,6 +32,7 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
+#include <unistd.h>
 #include "xf86str.h"
 #include "X11/Xatom.h"
 #include "micmap.h"