diff --git a/apps/emqx/src/emqx_metrics.erl b/apps/emqx/src/emqx_metrics.erl
index 70e660f28..ad1bb18ce 100644
--- a/apps/emqx/src/emqx_metrics.erl
+++ b/apps/emqx/src/emqx_metrics.erl
@@ -143,7 +143,7 @@
          %% PubSub Metrics
          {counter, 'messages.publish'},       % Messages Publish
          {counter, 'messages.dropped'},       % Messages dropped due to no subscribers
-         {counter, 'messages.dropped.expired'},  % QoS2 Messages expired
+         {counter, 'messages.dropped.await_pubrel_timeout'},  % QoS2 Messages expired
          {counter, 'messages.dropped.no_subscribers'},  % Messages dropped
          {counter, 'messages.forward'},       % Messages forward
          {counter, 'messages.delayed'},       % Messages delayed
@@ -552,7 +552,7 @@ reserved_idx('messages.qos2.received')       -> 106;
 reserved_idx('messages.qos2.sent')           -> 107;
 reserved_idx('messages.publish')             -> 108;
 reserved_idx('messages.dropped')             -> 109;
-reserved_idx('messages.dropped.expired')     -> 110;
+reserved_idx('messages.dropped.await_pubrel_timeout')     -> 110;
 reserved_idx('messages.dropped.no_subscribers') -> 111;
 reserved_idx('messages.forward')             -> 112;
 %%reserved_idx('messages.retained')            -> 113; %% keep the index, new metrics can use this
diff --git a/apps/emqx_management/src/emqx_mgmt_api_metrics.erl b/apps/emqx_management/src/emqx_mgmt_api_metrics.erl
index 5ebde4d11..4a58942ad 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_metrics.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_metrics.erl
@@ -69,7 +69,7 @@ properties() ->
         {'messages.delayed',                integer, <<"Number of delay- published messages stored by EMQ X Broker">>},
         {'messages.delivered',              integer, <<"Number of messages forwarded to the subscription process internally by EMQ X Broker">>},
         {'messages.dropped',                integer, <<"Total number of messages dropped by EMQ X Broker before forwarding to the subscription process">>},
-        {'messages.dropped.expired',        integer, <<"Number of messages dropped due to message expiration when receiving">>},
+        {'messages.dropped.await_pubrel_timeout', integer, <<"Number of messages dropped due to waiting PUBREL timeout">>},
         {'messages.dropped.no_subscribers', integer, <<"Number of messages dropped due to no subscribers">>},
         {'messages.forward',                integer, <<"Number of messages forwarded to other nodes">>},
         {'messages.publish',                integer, <<"Number of messages published in addition to system messages">>},
diff --git a/apps/emqx_prometheus/src/emqx_prometheus.erl b/apps/emqx_prometheus/src/emqx_prometheus.erl
index 3d4971f69..81d957591 100644
--- a/apps/emqx_prometheus/src/emqx_prometheus.erl
+++ b/apps/emqx_prometheus/src/emqx_prometheus.erl
@@ -403,7 +403,7 @@ emqx_collect(emqx_messages_dropped, Metrics) ->
     counter_metric(?C('messages.dropped', Metrics));
 
 emqx_collect(emqx_messages_dropped_expired, Metrics) ->
-    counter_metric(?C('messages.dropped.expired', Metrics));
+    counter_metric(?C('messages.dropped.await_pubrel_timeout', Metrics));
 
 emqx_collect(emqx_messages_dropped_no_subscribers, Metrics) ->
     counter_metric(?C('messages.dropped.no_subscribers', Metrics));