diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c
index 19ee635..a346e18 100644
--- a/arch/ia64/hp/sim/simserial.c
+++ b/arch/ia64/hp/sim/simserial.c
@@ -26,6 +26,7 @@
 #include <linux/fcntl.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
+#include <linux/capability.h>
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/serial.h>