diff --git a/src/server/game/Entities/Object/ObjectGuid.h b/src/server/game/Entities/Object/ObjectGuid.h
index b4b08d7ace..72fda2feb5 100644
--- a/src/server/game/Entities/Object/ObjectGuid.h
+++ b/src/server/game/Entities/Object/ObjectGuid.h
@@ -24,6 +24,7 @@
 #include <boost/functional/hash.hpp>
 
 #include <functional>
+#include <unordered_set>
 
 enum TypeID
 {
@@ -266,6 +267,7 @@ typedef std::set<ObjectGuid> GuidSet;
 typedef std::list<ObjectGuid> GuidList;
 typedef std::deque<ObjectGuid> GuidDeque;
 typedef std::vector<ObjectGuid> GuidVector;
+typedef std::unordered_set<ObjectGuid> GuidUnorderedSet;
 
 // maximum buffer size for packed guid is 18 bytes
 #define PACKED_GUID_MIN_BUFFER_SIZE 18
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 47b46f0575..b1b441e678 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -22042,13 +22042,13 @@ bool Player::IsVisibleGloballyFor(Player const* u) const
 }
 
 template<class T>
-inline void UpdateVisibilityOf_helper(GuidSet& s64, T* target, std::set<Unit*>& /*v*/)
+inline void UpdateVisibilityOf_helper(GuidUnorderedSet& s64, T* target, std::set<Unit*>& /*v*/)
 {
     s64.insert(target->GetGUID());
 }
 
 template<>
-inline void UpdateVisibilityOf_helper(GuidSet& s64, GameObject* target, std::set<Unit*>& /*v*/)
+inline void UpdateVisibilityOf_helper(GuidUnorderedSet& s64, GameObject* target, std::set<Unit*>& /*v*/)
 {
     // @HACK: This is to prevent objects like deeprun tram from disappearing when player moves far from its spawn point while riding it
     // But exclude stoppable elevators from this hack - they would be teleporting from one end to another
@@ -22059,14 +22059,14 @@ inline void UpdateVisibilityOf_helper(GuidSet& s64, GameObject* target, std::set
 }
 
 template<>
-inline void UpdateVisibilityOf_helper(GuidSet& s64, Creature* target, std::set<Unit*>& v)
+inline void UpdateVisibilityOf_helper(GuidUnorderedSet& s64, Creature* target, std::set<Unit*>& v)
 {
     s64.insert(target->GetGUID());
     v.insert(target);
 }
 
 template<>
-inline void UpdateVisibilityOf_helper(GuidSet& s64, Player* target, std::set<Unit*>& v)
+inline void UpdateVisibilityOf_helper(GuidUnorderedSet& s64, Player* target, std::set<Unit*>& v)
 {
     s64.insert(target->GetGUID());
     v.insert(target);
@@ -22128,7 +22128,7 @@ void Player::UpdateTriggerVisibility()
 
     UpdateData udata(GetMapId());
     WorldPacket packet;
-    for (GuidSet::iterator itr = m_clientGUIDs.begin(); itr != m_clientGUIDs.end(); ++itr)
+    for (auto itr = m_clientGUIDs.begin(); itr != m_clientGUIDs.end(); ++itr)
     {
         if (itr->IsCreature())
         {
@@ -23235,7 +23235,7 @@ void Player::UpdateForQuestWorldObjects()
 
     UpdateData udata(GetMapId());
     WorldPacket packet;
-    for (GuidSet::iterator itr = m_clientGUIDs.begin(); itr != m_clientGUIDs.end(); ++itr)
+    for (auto itr = m_clientGUIDs.begin(); itr != m_clientGUIDs.end(); ++itr)
     {
         if (itr->IsGameObject())
         {
diff --git a/src/server/game/Entities/Player/Player.h b/src/server/game/Entities/Player/Player.h
index d0cf22ca24..596693e5da 100644
--- a/src/server/game/Entities/Player/Player.h
+++ b/src/server/game/Entities/Player/Player.h
@@ -2435,7 +2435,7 @@ class Player : public Unit, public GridObject<Player>
         WorldLocation GetStartPosition() const;
 
         // currently visible objects at player client
-        GuidSet m_clientGUIDs;
+        GuidUnorderedSet m_clientGUIDs;
 
         bool HaveAtClient(WorldObject const* u) const;
 
diff --git a/src/server/game/Grids/Notifiers/GridNotifiers.cpp b/src/server/game/Grids/Notifiers/GridNotifiers.cpp
index 533f2845b1..d5562a9a3c 100644
--- a/src/server/game/Grids/Notifiers/GridNotifiers.cpp
+++ b/src/server/game/Grids/Notifiers/GridNotifiers.cpp
@@ -65,7 +65,7 @@ void VisibleNotifier::SendToSelf()
         }
     }
 
-    for (GuidSet::const_iterator it = vis_guids.begin(); it != vis_guids.end(); ++it)
+    for (auto it = vis_guids.begin(); it != vis_guids.end(); ++it)
     {
         i_player.m_clientGUIDs.erase(*it);
         i_data.AddOutOfRangeGUID(*it);
diff --git a/src/server/game/Grids/Notifiers/GridNotifiers.h b/src/server/game/Grids/Notifiers/GridNotifiers.h
index ae8c96aff9..0936f8ff75 100644
--- a/src/server/game/Grids/Notifiers/GridNotifiers.h
+++ b/src/server/game/Grids/Notifiers/GridNotifiers.h
@@ -45,7 +45,7 @@ namespace Trinity
         Player &i_player;
         UpdateData i_data;
         std::set<Unit*> i_visibleNow;
-        GuidSet vis_guids;
+        GuidUnorderedSet vis_guids;
 
         VisibleNotifier(Player &player) : i_player(player), i_data(player.GetMapId()), vis_guids(player.m_clientGUIDs) { }
         template<class T> void Visit(GridRefManager<T> &m);
diff --git a/src/server/game/Handlers/QuestHandler.cpp b/src/server/game/Handlers/QuestHandler.cpp
index 56126fb925..df5fae683f 100644
--- a/src/server/game/Handlers/QuestHandler.cpp
+++ b/src/server/game/Handlers/QuestHandler.cpp
@@ -619,7 +619,7 @@ void WorldSession::HandleQuestgiverStatusMultipleQuery(WorldPackets::Quest::Ques
 
     WorldPackets::Quest::QuestGiverStatusMultiple response;
 
-    for (GuidSet::const_iterator itr = _player->m_clientGUIDs.begin(); itr != _player->m_clientGUIDs.end(); ++itr)
+    for (auto itr = _player->m_clientGUIDs.begin(); itr != _player->m_clientGUIDs.end(); ++itr)
     {
         if (itr->IsAnyTypeCreature())
         {