diff --git a/src/mod_muc_admin.erl b/src/mod_muc_admin.erl
index 8a34f765f..9aa0fdbb5 100644
--- a/src/mod_muc_admin.erl
+++ b/src/mod_muc_admin.erl
@@ -264,7 +264,11 @@ get_commands_spec() ->
 
      #ejabberd_commands{name = send_direct_invitation, tags = [muc_room],
 			desc = "Send a direct invitation to several destinations",
-			longdesc = "Password and Message can also be: none. Users JIDs are separated with : ",
+			longdesc = "Since ejabberd 20.10, this command is "
+                        "asynchronous: the API call may return before the "
+                        "server has send all the invitations.\n\n"
+                        "Password and Message can also be: none. "
+                        "Users JIDs are separated with : ",
 			module = ?MODULE, function = send_direct_invitation,
 		        args_desc = ["Room name", "MUC service", "Password, or none",
 			 "Reason text, or none", "Users JIDs separated with : characters"],