diff --git a/server/gameserver/ingamevoice.cc b/server/gameserver/ingamevoice.cc
index b0851e77..b9e0c148 100644
--- a/server/gameserver/ingamevoice.cc
+++ b/server/gameserver/ingamevoice.cc
@@ -17,6 +17,17 @@ static void IncIntMap(std::map<int, int>& int_map, int key)
     }
 }
 
+static void DecIntMap(std::map<int, int>& int_map, int key)
+{
+    auto itr = int_map.find(key);
+    if (itr == int_map.end()) {
+        --itr->second;
+        if (itr->second < 0) {
+            itr->second = 0;
+        }
+    }
+}
+
 InGameVoice::InGameVoice(Room* room)
 {
     room_ = room;
@@ -66,50 +77,21 @@ void InGameVoice::OnHumanBeKill(int killer_id, Human* deader)
                  return true;
              });
     }
-}
-
-#if 0
-void InGameVoice::IncPersonalSeriesKills(int killer_id)
-{
-    auto itr = personal_series_kills_.find(killer_id);
-    if (itr != personal_series_kills_.end()) {
-        ++itr->second;
-    } else {
-        personal_series_kills_[killer_id] = 1;
+    {
+        room_->xtimer.SetTimeoutWpEx
+            (
+             SERVER_FRAME_RATE * 30,
+             [room = room_, killer_id] (int event, const a8::Args* args)
+             {
+                 if (a8::TIMER_EXEC_EVENT == event) {
+                     DecIntMap(room->GetInGameVoice()->personal_series_kills_, killer_id);
+                     DecIntMap(room->GetInGameVoice()->personal_nodead_series_kills_, killer_id);
+                 }
+             },
+             &room_->xtimer_attacher_);
     }
-    room_->xtimer.SetTimeoutWpEx
-        (
-         SERVER_FRAME_RATE * 30,
-         [room = room_, killer_id] (int event, const a8::Args* args)
-         {
-             if (a8::TIMER_EXEC_EVENT == event) {
-                 room->GetInGameVoice()->personal_series_kills_.erase(killer_id);
-             }
-         },
-         &room_->xtimer_attacher_);
 }
 
-void InGameVoice::IncPersonalNoDeadSeriesKills(int killer_id)
-{
-    auto itr = personal_nodead_series_kills_.find(killer_id);
-    if (itr != personal_nodead_series_kills_.end()) {
-        ++itr->second;
-    } else {
-        personal_nodead_series_kills_[killer_id] = 1;
-    }
-    room_->xtimer.SetTimeoutWpEx
-        (
-         SERVER_FRAME_RATE * 30,
-         [room = room_, killer_id] (int event, const a8::Args* args)
-         {
-             if (a8::TIMER_EXEC_EVENT == event) {
-                 room->GetInGameVoice()->personal_nodead_series_kills_.erase(killer_id);
-             }
-         },
-         &room_->xtimer_attacher_);
-}
-#endif
-
 void InGameVoice::Notify(Human* killer, Human* deader, const mt::InGameVoice* meta)
 {