diff --git a/mirai-core-api/src/commonMain/kotlin/message/deprecated.kt b/mirai-core-api/src/commonMain/kotlin/message/deprecated.kt
new file mode 100644
index 000000000..cfba95d74
--- /dev/null
+++ b/mirai-core-api/src/commonMain/kotlin/message/deprecated.kt
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2019-2020 Mamoe Technologies and contributors.
+ *
+ *  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ *  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ *  https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.message
+
+import net.mamoe.mirai.event.events.FriendMessageEvent
+import net.mamoe.mirai.event.events.GroupAwareMessageEvent
+import net.mamoe.mirai.event.events.GroupMessageEvent
+import net.mamoe.mirai.event.events.MessageEvent
+import net.mamoe.mirai.event.events.MessageEventExtensions
+import net.mamoe.mirai.event.events.MessageEventPlatformExtensions
+import net.mamoe.mirai.event.events.TempMessageEvent
+import net.mamoe.mirai.event.events.UserMessageEvent
+import net.mamoe.mirai.utils.PlannedRemoval
+
+// internal 定义可以通过全名引用, 用户就能看到 ReplaceWith. 新用户则看不到这些旧类型的 import.
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("FriendMessageEvent", "net.mamoe.mirai.event.events.FriendMessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias FriendMessageEvent = FriendMessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("GroupAwareMessageEvent", "net.mamoe.mirai.event.events.GroupAwareMessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias GroupAwareMessageEvent = GroupAwareMessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("GroupMessageEvent", "net.mamoe.mirai.event.events.GroupMessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias GroupMessageEvent = GroupMessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("MessageEvent", "net.mamoe.mirai.event.events.MessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias MessageEvent = MessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("TempMessageEvent", "net.mamoe.mirai.event.events.TempMessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias TempMessageEvent = TempMessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("UserMessageEvent", "net.mamoe.mirai.event.events.UserMessageEvent"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias UserMessageEvent = UserMessageEvent
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("MessageEventExtensions", "net.mamoe.mirai.event.events.MessageEventExtensions"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias MessageEventExtensions<TSender, TSubject> = MessageEventExtensions<TSender, TSubject>
+
+@PlannedRemoval("2.0-M2")
+@Deprecated(
+    "Replace with new package.",
+    ReplaceWith("MessageEventPlatformExtensions", "net.mamoe.mirai.event.events.MessageEventPlatformExtensions"),
+    level = DeprecationLevel.ERROR
+)
+internal typealias MessageEventPlatformExtensions<TSender, TSubject> = MessageEventPlatformExtensions<TSender, TSubject>
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