diff --git a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/events/BotEvents.kt b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/events/BotEvents.kt
index d2ad8a298..8c6fd6e0e 100644
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/events/BotEvents.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/event/events/BotEvents.kt
@@ -155,6 +155,8 @@ val MessageRecallEvent.GroupRecall.author: Member
     get() = if (authorId == bot.id) group.botAsMember else group[authorId]
 
 val MessageRecallEvent.FriendRecall.isByBot: Boolean get() = this.operator == bot.id
+// val MessageRecallEvent.GroupRecall.isByBot: Boolean get() = (this as GroupOperableEvent).isByBot
+// no need
 
 val MessageRecallEvent.isByBot: Boolean
     get() = when (this) {