diff --git a/apps/emqx_bridge_s3/src/emqx_bridge_s3_connector.erl b/apps/emqx_bridge_s3/src/emqx_bridge_s3_connector.erl
index 204a84a65..60e2c9b87 100644
--- a/apps/emqx_bridge_s3/src/emqx_bridge_s3_connector.erl
+++ b/apps/emqx_bridge_s3/src/emqx_bridge_s3_connector.erl
@@ -373,7 +373,7 @@ run_aggregated_upload(InstId, ChannelID, Records, #{aggreg_id := AggregId}) ->
             ?tp(s3_bridge_aggreg_push_ok, #{instance_id => InstId, name => AggregId}),
             ok;
         {error, Reason} ->
-            {error, {unrecoverable_error, Reason}}
+            {error, {unrecoverable_error, emqx_utils:explain_posix(Reason)}}
     end.
 
 map_error(Error) ->