diff --git a/main/pbx.c b/main/pbx.c
index eaa0c20e9e05fc659d8d90372003b40452d300af..a915e1f40466e44138d851f6ec8ca5d888ff6f85 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -4105,6 +4105,7 @@ static void set_ext_pri(struct ast_channel *c, const char *exten, int pri)
 
 /*!
  * \brief collect digits from the channel into the buffer.
+ * \param waittime is in milliseconds
  * \retval 0 on timeout or done.
  * \retval -1 on error.
 */