diff --git a/telethon_generator/data/errors.csv b/telethon_generator/data/errors.csv
index 8d2248a1..e93e96c0 100644
--- a/telethon_generator/data/errors.csv
+++ b/telethon_generator/data/errors.csv
@@ -155,7 +155,7 @@ GROUPCALL_FORBIDDEN,403,
 GROUPCALL_JOIN_MISSING,400,
 GROUPCALL_SSRC_DUPLICATE_MUCH,400,
 GROUPCALL_NOT_MODIFIED,400,
-GROUPCALL_ADD_PARTICIPANTS_FAILED,500,
+GROUPCALL_ADD_PARTICIPANTS_FAILED,500,The params passed in phone.JoinGroupCall is invalid
 GROUPED_MEDIA_INVALID,400,Invalid grouped media
 GROUP_CALL_INVALID,400,Group call invalid
 HASH_INVALID,400,The provided hash is invalid