diff --git a/include/nuttx/hrtimer.h b/include/nuttx/hrtimer.h
index 0bf3cc90996..9b8a33fcc5f 100644
--- a/include/nuttx/hrtimer.h
+++ b/include/nuttx/hrtimer.h
@@ -66,7 +66,7 @@ typedef struct hrtimer_node_s hrtimer_node_t;
  */
 
 typedef CODE uint64_t
-(*hrtimer_cb)(FAR hrtimer_t *hrtimer, uint64_t expired);
+(*hrtimer_cb)(FAR const hrtimer_t *hrtimer, uint64_t expired);
 
 /* Red-black tree node used to order hrtimers by expiration time */