diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 78488e0..7ec5b86 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -73,6 +73,7 @@
 extern int watchdog_thresh;
 extern unsigned long *watchdog_cpumask_bits;
 extern int sysctl_softlockup_all_cpu_backtrace;
+extern int sysctl_hardlockup_all_cpu_backtrace;
 struct ctl_table;
 extern int proc_watchdog(struct ctl_table *, int ,
 			 void __user *, size_t *, loff_t *);