diff --git a/compiler/error/source/400_BAD_REQUEST.csv b/compiler/error/source/400_BAD_REQUEST.csv
index 71014ba0..940d2837 100644
--- a/compiler/error/source/400_BAD_REQUEST.csv
+++ b/compiler/error/source/400_BAD_REQUEST.csv
@@ -28,4 +28,5 @@ PASSWORD_HASH_INVALID|Two-step verification password is invalid
 USERNAME_NOT_OCCUPIED|The username is not occupied by anyone
 USERNAME_INVALID|The username is invalid
 MESSAGE_ID_INVALID|The message id is invalid
-MESSAGE_NOT_MODIFIED|The message was not modified
\ No newline at end of file
+MESSAGE_NOT_MODIFIED|The message was not modified
+ENTITY_MENTION_USER_INVALID|The mentioned entity is not an user
\ No newline at end of file