diff --git a/board/Synology/ds109/ds109.c b/board/Synology/ds109/ds109.c
index 3914faa..9e7f6ac 100644
--- a/board/Synology/ds109/ds109.c
+++ b/board/Synology/ds109/ds109.c
@@ -10,6 +10,7 @@
 #include <miiphy.h>
 #include <net.h>
 #include <asm/global_data.h>
+#include <asm/io.h>
 #include <asm/setup.h>
 #include <asm/arch/cpu.h>
 #include <asm/arch/soc.h>