diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index bc5ee99b9c23787594677fa0a5eac4364b732a0d..73e6614cdf848d66b12a79ff322830d7ac022216 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -587,6 +587,8 @@ int hpet_register(struct hpet_task *tp, int periodic)
 		return -EINVAL;
 	}
 
+	tp->ht_opaque = NULL;
+
 	spin_lock_irq(&hpet_task_lock);
 	spin_lock(&hpet_lock);