diff --git a/apps/emqx_retainer/src/emqx_retainer_mnesia.erl b/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
index 0152c240e..0d407ea78 100644
--- a/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
+++ b/apps/emqx_retainer/src/emqx_retainer_mnesia.erl
@@ -263,12 +263,22 @@ reindex_status() ->
 
 do_store_retained(Msg, TopicTokens, ExpiryTime) ->
     %% Retained message is stored syncronously on all core nodes
+    %%
+    %% No transaction, meaning that concurrent writes in the cluster may
+    %% lead to inconsistent replicas. This could manifest in two clients
+    %% getting different retained messages for the same topic, depending
+    %% on which node they are connected to. We tolerate that.
     ok = do_store_retained_message(Msg, TopicTokens, ExpiryTime),
     %% Since retained message was stored syncronously on all core nodes,
     %% now we are sure that
     %% * either we will write correct indices
     %% * or if we a replicant with outdated write indices due to reindexing,
     %%   the correct indices will be added by reindexing
+    %%
+    %% No transacation as well, meaning that concurrent writes in the cluster
+    %% may lead to inconsistent index replicas. This essentially allows for
+    %% inconsistent query results, where index entry has different expiry time
+    %% than the message it points to.
     ok = do_store_retained_indices(TopicTokens, ExpiryTime).
 
 do_store_retained_message(Msg, TopicTokens, ExpiryTime) ->
@@ -281,18 +291,20 @@ do_store_retained_message(Msg, TopicTokens, ExpiryTime) ->
 
 do_store_retained_indices(TopicTokens, ExpiryTime) ->
     Indices = dirty_indices(write),
-    ok = emqx_retainer_index:foreach_index_key(
-        fun(Key) -> do_store_retained_index(Key, ExpiryTime) end,
-        Indices,
-        TopicTokens
-    ).
+    ok = mria:async_dirty(?RETAINER_SHARD, fun() ->
+        emqx_retainer_index:foreach_index_key(
+            fun(Key) -> do_store_retained_index(Key, ExpiryTime) end,
+            Indices,
+            TopicTokens
+        )
+    end).
 
 do_store_retained_index(Key, ExpiryTime) ->
     RetainedIndex = #retained_index{
         key = Key,
         expiry_time = ExpiryTime
     },
-    mria:dirty_write(?TAB_INDEX, RetainedIndex).
+    mnesia:write(?TAB_INDEX, RetainedIndex, write).
 
 msg_table(SearchTable) ->
     qlc:q([