diff --git a/arch/mips/include/asm/mach-ralink/ralink_regs.h b/arch/mips/include/asm/mach-ralink/ralink_regs.h
index 9df1a53bcb36..b4e7dfa214eb 100644
--- a/arch/mips/include/asm/mach-ralink/ralink_regs.h
+++ b/arch/mips/include/asm/mach-ralink/ralink_regs.h
@@ -13,6 +13,8 @@
 #ifndef _RALINK_REGS_H_
 #define _RALINK_REGS_H_
 
+#include <linux/io.h>
+
 enum ralink_soc_type {
 	RALINK_UNKNOWN = 0,
 	RT2880_SOC,