diff --git a/server/gameserver/buff.cc b/server/gameserver/buff.cc
index e58eb5c9..568e2bb4 100644
--- a/server/gameserver/buff.cc
+++ b/server/gameserver/buff.cc
@@ -325,7 +325,7 @@ void Buff::ProcSputteringFunc(Bullet* bullet)
              0,
              0,
              nullptr);
-        VirtualBullet* p = new VirtualBullet();
+        std::shared_ptr<VirtualBullet> p = std::make_shared<VirtualBullet>();
         p->bullet_uniid = bullet_uniid;
         p->weapon_uniid = bullet->weapon_uniid;
         p->skill_meta = bullet->skill_meta;
@@ -339,7 +339,12 @@ void Buff::ProcSputteringFunc(Bullet* bullet)
         p->born_pos = bullet_born_pos;
         p->born_dir = bullet_dir;
         p->Init();
-        owner->room->AddTask(bullet_uniid, p);
+        owner->room->AddTask(bullet_uniid, std::make_shared<a8::CommonCbProcEx>
+                             (
+                              [p] (const a8::Args* args)
+                              {
+                                  p->Update(50);
+                              }));
     }
 
 }
diff --git a/server/gameserver/room.cc b/server/gameserver/room.cc
index fae8f1c8..af76885a 100644
--- a/server/gameserver/room.cc
+++ b/server/gameserver/room.cc
@@ -162,6 +162,7 @@ void Room::UnInit()
         delete pair.second;
     }
     discard_team_hash_.clear();
+    task_hash_.clear();
     A8_SAFE_DELETE(frame_event_data);
     PerfMonitor::Instance()->alive_count -= alive_count_;
 }
@@ -194,9 +195,7 @@ void Room::Update(int delta_time)
             pair.second->Update(50);
         }
         for (auto& pair : task_hash_) {
-            if (!pair.second->IsDone()) {
-                pair.second->Update(50);
-            }
+            (*pair.second)(nullptr);
         }
 #ifdef DEBUG1
         end_tick = a8::XGetTickCount();
@@ -3488,12 +3487,12 @@ bool Room::IsAllRealDead()
     return is_all_dead;
 }
 
-void Room::AddTask(int task_uniid, ITask* task)
+void Room::AddTask(int task_uniid, std::shared_ptr<a8::CommonCbProcEx> cb)
 {
     if (task_hash_.find(task_uniid) != task_hash_.end()) {
         abort();
     }
-    task_hash_[task_uniid] = task;
+    task_hash_[task_uniid] = cb;
 }
 
 void Room::RemoveTask(int task_uniid)
diff --git a/server/gameserver/room.h b/server/gameserver/room.h
index 81d96def..16bdb391 100644
--- a/server/gameserver/room.h
+++ b/server/gameserver/room.h
@@ -223,7 +223,7 @@ public:
     bool IsInfiniteBulletMode() { return infinite_bullet_mode_; };
     void AddToPostBattleAutoFreeList(a8::XTimerWp timer);
     bool CanAddObstacle(const glm::vec3& pos, int obstacle_id);
-    void AddTask(int task_uniid, ITask* task);
+    void AddTask(int task_uniid, std::shared_ptr<a8::CommonCbProcEx> cb);
     void RemoveTask(int task_uniid);
     const mt::AirLine* GetAirLine() { return airline_; }
     int GetPolyExtFlag(int poly_idx);
@@ -373,7 +373,7 @@ private:
     std::map<int, Human*> alive_player_hash_;
     std::map<int, Human*> last_human_hash_;
     std::map<int, std::shared_ptr<BornPoint>> born_point_hash_;
-    std::map<int, ITask*> task_hash_;
+    std::map<int, std::shared_ptr<a8::CommonCbProcEx>> task_hash_;
 
     std::map<int, CarObject> car_hash_;
     std::map<int, Human*> removed_robot_hash_;
diff --git a/server/gameserver/types.h b/server/gameserver/types.h
index a935d4f2..82c52a51 100644
--- a/server/gameserver/types.h
+++ b/server/gameserver/types.h
@@ -37,13 +37,6 @@ struct BulletCheckResult
     std::set<Entity*> objects;
 };
 
-class ITask
-{
- public:
-    virtual void Update(int delta_time) = 0;
-    virtual bool IsDone() = 0;
-};
-
 class DelayAddBuffHandle
 {
 public:
diff --git a/server/gameserver/virtualbullet.h b/server/gameserver/virtualbullet.h
index 98b573b9..28815d0f 100644
--- a/server/gameserver/virtualbullet.h
+++ b/server/gameserver/virtualbullet.h
@@ -4,7 +4,7 @@ struct GridCell;
 class Entity;
 class Room;
 class Obstacle;
-class VirtualBullet : public IBullet, public ITask
+class VirtualBullet : public IBullet
 {
  public:
     int bullet_uniid = 0;
@@ -35,8 +35,8 @@ class VirtualBullet : public IBullet, public ITask
     virtual float GetHitRadius() override;
     virtual void ProcRequestBulletDmg(int shield_hit, int strength_wall_uniid, int target_uniid, const glm::vec3& pos) override;
 
-    virtual void Update(int delta_time) override;
-    virtual bool IsDone() override;
+    virtual void Update(int delta_time);
+    virtual bool IsDone();
 
     void Init();
     void SetPos(Position pos) { pos_ = pos; };
diff --git a/third_party/a8 b/third_party/a8
index 54fe50ed..140a61cc 160000
--- a/third_party/a8
+++ b/third_party/a8
@@ -1 +1 @@
-Subproject commit 54fe50edf11dda774dcd6fc480134c9e4ce449cd
+Subproject commit 140a61cc7f6c23602d05963ab868fe9f5d36cc44