diff --git a/drivers/isdn/hisax/hfc4s8s_l1.c b/drivers/isdn/hisax/hfc4s8s_l1.c
index 1ac46c26b9363f72a48edd751d9c65a11d163548..ba1d028343ecd8e869a39d971d6a5d27e74b94e5 100644
--- a/drivers/isdn/hisax/hfc4s8s_l1.c
+++ b/drivers/isdn/hisax/hfc4s8s_l1.c
@@ -29,6 +29,7 @@
 #include <linux/timer.h>
 #include <linux/skbuff.h>
 #include <linux/wait.h>
+#include <asm/io.h>
 #include "hisax_if.h"
 #include "hfc4s8s_l1.h"