diff --git a/apps/emqx/src/emqx_channel.erl b/apps/emqx/src/emqx_channel.erl
index ea35abfba..3b18c20cb 100644
--- a/apps/emqx/src/emqx_channel.erl
+++ b/apps/emqx/src/emqx_channel.erl
@@ -2134,10 +2134,14 @@ will_delay_interval(WillMsg) ->
         0
     ).
 
-publish_will_msg(ClientInfo, Msg = #message{topic = Topic}) ->
+publish_will_msg(
+    ClientInfo = #{mountpoint := MountPoint},
+    Msg = #message{topic = Topic}
+) ->
     case emqx_access_control:authorize(ClientInfo, publish, Topic) of
         allow ->
-            _ = emqx_broker:publish(Msg),
+            NMsg = emqx_mountpoint:mount(MountPoint, Msg),
+            _ = emqx_broker:publish(NMsg),
             ok;
         deny ->
             ?tp(
diff --git a/apps/emqx/test/emqx_channel_SUITE.erl b/apps/emqx/test/emqx_channel_SUITE.erl
index a3fa3e5bc..153f0417d 100644
--- a/apps/emqx/test/emqx_channel_SUITE.erl
+++ b/apps/emqx/test/emqx_channel_SUITE.erl
@@ -728,6 +728,22 @@ t_quota_qos2(_) ->
     del_bucket(),
     esockd_limiter:stop().
 
+t_mount_will_msg(_) ->
+    Self = self(),
+    ClientInfo = clientinfo(#{mountpoint => <<"prefix/">>}),
+    Msg = emqx_message:make(test, <<"will_topic">>, <<"will_payload">>),
+    Channel = channel(#{clientinfo => ClientInfo, will_msg => Msg}),
+
+    ok = meck:expect(emqx_broker, publish, fun(M) -> Self ! {pub, M} end),
+
+    {shutdown, kicked, ok, ?DISCONNECT_PACKET(?RC_ADMINISTRATIVE_ACTION), _} = emqx_channel:handle_call(
+        kick, Channel
+    ),
+    receive
+        {pub, #message{topic = <<"prefix/will_topic">>}} -> ok
+    after 200 -> exit(will_message_not_published_or_not_correct)
+    end.
+
 %%--------------------------------------------------------------------
 %% Test cases for handle_deliver
 %%--------------------------------------------------------------------
diff --git a/changes/v5.0.11-en.md b/changes/v5.0.11-en.md
index 59ef42b4d..d83f9d435 100644
--- a/changes/v5.0.11-en.md
+++ b/changes/v5.0.11-en.md
@@ -29,3 +29,5 @@
 - Fix that JWT ACL rules are only applied if an `exp` claim is set [#9368](https://github.com/emqx/emqx/pull/9368).
 
 - Fix that `/configs/global_zone` API cannot get the default value of the configuration [#9392](https://github.com/emqx/emqx/pull/9392).
+
+- Fix mountpoint not working for will-msg [#9399](https://github.com/emqx/emqx/pull/9399).
diff --git a/changes/v5.0.11-zh.md b/changes/v5.0.11-zh.md
index b48c09e7a..6bc12c5cd 100644
--- a/changes/v5.0.11-zh.md
+++ b/changes/v5.0.11-zh.md
@@ -26,3 +26,5 @@
 - 修复 JWT ACL 规则只在设置了超期时间时才生效的问题 [#9368](https://github.com/emqx/emqx/pull/9368)。
 
 - 修复 `/configs/global_zone` API 无法正确获取配置的默认值问题 [#9392](https://github.com/emqx/emqx/pull/9392)。
+
+- 修复 mountpoint 配置未对遗嘱消息生效的问题 [#9399](https://github.com/emqx/emqx/pull/9399)