diff --git a/apps/emqx/src/emqx_persistent_message_ds_replayer.erl b/apps/emqx/src/emqx_persistent_message_ds_replayer.erl
index 2f5348938..64b9cabb4 100644
--- a/apps/emqx/src/emqx_persistent_message_ds_replayer.erl
+++ b/apps/emqx/src/emqx_persistent_message_ds_replayer.erl
@@ -266,8 +266,9 @@ replay_range(
             _ ->
                 lists:nthtail(range_size(First, FirstUnacked), Messages)
         end,
+    MessagesReplay = [emqx_message:set_flag(dup, true, Msg) || Msg <- MessagesUnacked],
     %% Asserting that range is consistent with the message storage state.
-    {Replies, Until} = publish(FirstUnacked, MessagesUnacked),
+    {Replies, Until} = publish(FirstUnacked, MessagesReplay),
     %% Again, we need to keep the iterator pointing past the end of the
     %% range, so that we can pick up where we left off.
     Range = Range0#ds_pubrange{iterator = ItNext},
diff --git a/apps/emqx/test/emqx_persistent_session_SUITE.erl b/apps/emqx/test/emqx_persistent_session_SUITE.erl
index 3f4cbcd28..77b625f05 100644
--- a/apps/emqx/test/emqx_persistent_session_SUITE.erl
+++ b/apps/emqx/test/emqx_persistent_session_SUITE.erl
@@ -675,6 +675,12 @@ t_publish_many_while_client_is_gone_qos1(Config) ->
     ?assert(NMsgs2 > NPubs2, Msgs2),
     ?assert(NMsgs2 >= NPubs - NAcked, Msgs2),
     NSame = NMsgs2 - NPubs2,
+    ?assert(
+        lists:all(fun(#{dup := Dup}) -> Dup end, lists:sublist(Msgs2, NSame))
+    ),
+    ?assertNot(
+        lists:all(fun(#{dup := Dup}) -> Dup end, lists:nthtail(NSame, Msgs2))
+    ),
     ?assertEqual(
         [maps:with([packet_id, topic, payload], M) || M <- lists:nthtail(NMsgs1 - NSame, Msgs1)],
         [maps:with([packet_id, topic, payload], M) || M <- lists:sublist(Msgs2, NSame)]