diff --git a/kernel/futex.c b/kernel/futex.c
index 6b50a024bca2..eef8cd26b5e5 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -883,7 +883,12 @@ retry_private:
 out_unlock:
 	double_unlock_hb(hb1, hb2);
 
-	/* drop_futex_key_refs() must be called outside the spinlocks. */
+	/*
+	 * drop_futex_key_refs() must be called outside the spinlocks. During
+	 * the requeue we moved futex_q's from the hash bucket at key1 to the
+	 * one at key2 and updated their key pointer.  We no longer need to
+	 * hold the references to key1.
+	 */
 	while (--drop_count >= 0)
 		drop_futex_key_refs(&key1);