diff --git a/os/kernel/src/chmboxes.c b/os/kernel/src/chmboxes.c
index 50ce22b7f..860e92db9 100644
--- a/os/kernel/src/chmboxes.c
+++ b/os/kernel/src/chmboxes.c
@@ -58,7 +58,7 @@
  *
  * @param[out] mbp      the pointer to the Mailbox structure to be initialized
  * @param[in] buf       pointer to the messages buffer as an array of @p msg_t
- * @param[in] n         size of the buffer as number of @p msg_t
+ * @param[in] n         number of elements in the buffer array
  *
  * @init
  */