diff --git a/arch/sandbox/include/asm/io.h b/arch/sandbox/include/asm/io.h
index b87ee19427f10b489865a3b8cff2c6a2cda155d7..69196329d76a5924bb1969c4917910c000d17a29 100644
--- a/arch/sandbox/include/asm/io.h
+++ b/arch/sandbox/include/asm/io.h
@@ -56,6 +56,21 @@ void outl(unsigned int value, unsigned int addr);
 void outw(unsigned int value, unsigned int addr);
 void outb(unsigned int value, unsigned int addr);
 
+static inline void _insw(volatile u16 *port, void *buf, int ns)
+{
+}
+
+static inline void _outsw(volatile u16 *port, const void *buf, int ns)
+{
+}
+
+#define insw(port, buf, ns)		_insw((u16 *)port, buf, ns)
+#define outsw(port, buf, ns)		_outsw((u16 *)port, buf, ns)
+
+/* For systemace.c */
+#define out16(addr, val)
+#define in16(addr)		0
+
 #include <iotrace.h>
 #include <asm/types.h>