diff --git a/src/server/game/AI/CoreAI/PassiveAI.cpp b/src/server/game/AI/CoreAI/PassiveAI.cpp
index 080827f1a..796231e41 100644
--- a/src/server/game/AI/CoreAI/PassiveAI.cpp
+++ b/src/server/game/AI/CoreAI/PassiveAI.cpp
@@ -25,7 +25,7 @@ NullCreatureAI::NullCreatureAI(Creature* c) : CreatureAI(c) { me->SetReactState(
 
 int32 NullCreatureAI::Permissible(Creature const* creature)
 {
-    if (creature->HasFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_SPELLCLICK))
+    if (creature->HasNpcFlag(UNIT_NPC_FLAG_SPELLCLICK))
         return PERMIT_BASE_PROACTIVE + 50;
 
     if (creature->IsTrigger())
diff --git a/src/server/game/AI/SmartScripts/SmartScript.cpp b/src/server/game/AI/SmartScripts/SmartScript.cpp
index efac02f80..c680cc4cc 100644
--- a/src/server/game/AI/SmartScripts/SmartScript.cpp
+++ b/src/server/game/AI/SmartScripts/SmartScript.cpp
@@ -2061,21 +2061,21 @@ void SmartScript::ProcessAction(SmartScriptHolder& e, Unit* unit, uint32 var0, u
         {
             for (WorldObject* target : targets)
                 if (IsCreature(target))
-                    target->ToUnit()->SetUInt32Value(UNIT_NPC_FLAGS, e.action.unitFlag.flag);
+                    target->ToUnit()->ReplaceAllNpcFlags(NPCFlags(e.action.unitFlag.flag));
             break;
         }
         case SMART_ACTION_ADD_NPC_FLAG:
         {
             for (WorldObject* target : targets)
                 if (IsCreature(target))
-                    target->ToUnit()->SetFlag(UNIT_NPC_FLAGS, e.action.unitFlag.flag);
+                    target->ToUnit()->SetNpcFlag(NPCFlags(e.action.unitFlag.flag));
             break;
         }
         case SMART_ACTION_REMOVE_NPC_FLAG:
         {
             for (WorldObject* target : targets)
                 if (IsCreature(target))
-                    target->ToUnit()->RemoveFlag(UNIT_NPC_FLAGS, e.action.unitFlag.flag);
+                    target->ToUnit()->RemoveNpcFlag(NPCFlags(e.action.unitFlag.flag));
             break;
         }
         case SMART_ACTION_CROSS_CAST:
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index bdd01d230..97efd9c2f 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1003,13 +1003,12 @@ public:
     [[nodiscard]] bool IsInnkeeper()    const { return HasNpcFlag(UNIT_NPC_FLAG_INNKEEPER); }
     [[nodiscard]] bool IsSpiritHealer() const { return HasNpcFlag(UNIT_NPC_FLAG_SPIRITHEALER); }
     [[nodiscard]] bool IsSpiritGuide()  const { return HasNpcFlag(UNIT_NPC_FLAG_SPIRITGUIDE); }
-    [[nodiscard]] bool IsTabardDesigner()const { return HasNpcFlag(UNIT_NPC_FLAG_TABARDDESIGNER); }
+    [[nodiscard]] bool IsTabardDesigner() const { return HasNpcFlag(UNIT_NPC_FLAG_TABARDDESIGNER); }
     [[nodiscard]] bool IsAuctioner()    const { return HasNpcFlag(UNIT_NPC_FLAG_AUCTIONEER); }
     [[nodiscard]] bool IsArmorer()      const { return HasNpcFlag(UNIT_NPC_FLAG_REPAIR); }
     [[nodiscard]] bool IsServiceProvider() const
     {
-        return HasFlag(UNIT_NPC_FLAGS,
-                       UNIT_NPC_FLAG_VENDOR | UNIT_NPC_FLAG_TRAINER | UNIT_NPC_FLAG_FLIGHTMASTER |
+        return HasNpcFlag(UNIT_NPC_FLAG_VENDOR | UNIT_NPC_FLAG_TRAINER | UNIT_NPC_FLAG_FLIGHTMASTER |
                        UNIT_NPC_FLAG_PETITIONER | UNIT_NPC_FLAG_BATTLEMASTER | UNIT_NPC_FLAG_BANKER |
                        UNIT_NPC_FLAG_INNKEEPER | UNIT_NPC_FLAG_SPIRITHEALER |
                        UNIT_NPC_FLAG_SPIRITGUIDE | UNIT_NPC_FLAG_TABARDDESIGNER | UNIT_NPC_FLAG_AUCTIONEER);
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal.cpp
index b527b96b7..01b12a9ef 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/BattleForMountHyjal/hyjal.cpp
@@ -113,7 +113,7 @@ public:
             scheduler.CancelAll();
             if (InstanceScript* hyjal = me->GetInstanceScript())
                 if (!hyjal->GetData(DATA_WAVE_STATUS))
-                    me->SetFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_GOSSIP);
+                    me->SetNpcFlag(UNIT_NPC_FLAG_GOSSIP);
         }
 
         void JustEngagedWith(Unit* /*who*/) override
@@ -138,7 +138,7 @@ public:
 
         void IsSummonedBy(WorldObject* /*summoner*/) override
         {
-            me->RemoveFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_GOSSIP);
+            me->RemoveNpcFlag(UNIT_NPC_FLAG_GOSSIP);
             DoCastSelf(SPELL_SIMPLE_TELEPORT, true);
 
             // Should wait 2400ms
@@ -176,7 +176,7 @@ public:
 
     bool OnGossipSelect(Player* /*player*/ , Creature* creature, uint32 /*sender*/, uint32 /*action*/) override
     {
-        creature->RemoveFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_GOSSIP);
+        creature->RemoveNpcFlag(UNIT_NPC_FLAG_GOSSIP);
 
         if (InstanceScript* hyjal = creature->GetInstanceScript())
         {
@@ -213,7 +213,7 @@ public:
             scheduler.CancelAll();
             if (InstanceScript* hyjal = me->GetInstanceScript())
                 if (!hyjal->GetData(DATA_WAVE_STATUS))
-                    me->SetFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_GOSSIP);
+                    me->SetNpcFlag(UNIT_NPC_FLAG_GOSSIP);
         }
 
         void JustEngagedWith(Unit* /*who*/) override
@@ -251,7 +251,7 @@ public:
 
     bool OnGossipSelect(Player* /*player*/, Creature* creature, uint32 /*sender*/, uint32 /*action*/) override
     {
-        creature->RemoveFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_GOSSIP);
+        creature->RemoveNpcFlag(UNIT_NPC_FLAG_GOSSIP);
 
         if (InstanceScript* hyjal = creature->GetInstanceScript())
         {
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_yoggsaron.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_yoggsaron.cpp
index b9f4f71f3..dc2e9c641 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_yoggsaron.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_yoggsaron.cpp
@@ -1790,7 +1790,7 @@ public:
             if (!spellClickHandled)
                 return;
 
-            if (!me->GetUInt32Value(UNIT_NPC_FLAGS))
+            if (!me->GetNpcFlags())
                 return;
 
             switch (me->GetArmor())
@@ -1806,7 +1806,7 @@ public:
                     break;
             }
 
-            me->SetUInt32Value(UNIT_NPC_FLAGS, 0);
+            me->ReplaceAllNpcFlags(UNIT_NPC_FLAG_NONE);
             me->DespawnOrUnsummon(1000);
         }