diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 5912874..71d2b8a 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -90,6 +90,8 @@
 #define nmi_enter()		irq_enter()
 #define nmi_exit()		sub_preempt_count(HARDIRQ_OFFSET)
 
+struct task_struct;
+
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
 static inline void account_user_vtime(struct task_struct *tsk)
 {