diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 4fc379d..fca9302 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -138,6 +138,7 @@
 			      struct timespec __user *rmtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
+extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
 
 extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 				 struct task_struct *tsk);