diff --git a/server/gameserver/pbutils.cc b/server/gameserver/pbutils.cc
index 12c5e28c..018ef02e 100644
--- a/server/gameserver/pbutils.cc
+++ b/server/gameserver/pbutils.cc
@@ -1436,6 +1436,11 @@ void Human::FillMFGasData(cs::MFGasData* gas_data)
             long long duration = room->GetGasData().old_area_meta->wait_time() * 20 -
                 (room->GetFrameNo() - room->GetGasData().gas_start_frameno);
             gas_data->set_duration(std::max(duration * 50, (long long)1000) / 1000);
+            {
+                long long passed_frame_num = room->GetFrameNo() - room->GetGasData().gas_start_frameno;
+                float time = std::max(0.0f, gas_data->duration() - passed_frame_num / SERVER_FRAME_RATE) + 1;
+                gas_data->set_total_duration(time);
+            }
         }
         if (room->IsPveRoom()) {
             gas_data->set_duration(0);