diff --git a/data/sql/updates/pending_db_world/rev_1782661989089356961.sql b/data/sql/updates/pending_db_world/rev_1782661989089356961.sql
new file mode 100644
index 0000000000..5d4ee9eb52
--- /dev/null
+++ b/data/sql/updates/pending_db_world/rev_1782661989089356961.sql
@@ -0,0 +1,11 @@
+--
+-- 62375 Gathering Speed is not removed by Evade
+-- SPELL_ATTR0_CU_IGNORE_EVADE = 0x00000800
+DELETE FROM `spell_custom_attr` WHERE `spell_id` = 62375;
+INSERT INTO `spell_custom_attr` (`spell_id`, `attributes`) VALUES (62375, 0x800);
+
+-- Flame Leviathan
+UPDATE `creature_template_addon` SET `visibilityDistanceType` = 4 WHERE (`entry` IN (33113, 33114, 33139, 34003, 34111, 33143));
+
+-- Ulduar Colossus
+UPDATE `creature_addon` SET `visibilityDistanceType`=4 WHERE `guid` IN (137476, 137477, 137478, 137479, 137480)
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_flame_leviathan.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_flame_leviathan.cpp
index f763c60a45..a1cb2ebec9 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_flame_leviathan.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_flame_leviathan.cpp
@@ -121,7 +121,6 @@ enum Events
     EVENT_MIMIRONS_INFERNO              = 8,
     EVENT_THORIMS_HAMMER                = 9,
     EVENT_SOUND_BEGINNING               = 10,
-    EVENT_POSITION_CHECK                = 11,
 };
 
 enum Texts
@@ -209,13 +208,13 @@ struct boss_flame_leviathan : public BossAI
     void ScheduleEvents();
     void SummonTowerHelpers(uint8 towerId);
 
-    // Original
     void JustReachedHome() override
     {
         _JustReachedHome();
         // For achievement
         instance->StorePersistentData(PERSISTENT_DATA_UNBROKEN, 0);
         me->setActive(false);
+        me->RemoveAurasDueToSpell(SPELL_GATHERING_SPEED);
     }
 
     void MoveInLineOfSight(Unit*) override {}
@@ -380,14 +379,6 @@ struct boss_flame_leviathan : public BossAI
 
         switch (events.ExecuteEvent())
         {
-            case EVENT_POSITION_CHECK:
-                if (me->GetPositionX() > 450 || me->GetPositionX() < 120)
-                {
-                    EnterEvadeMode();
-                    return;
-                }
-                events.Repeat(5s);
-                break;
             case EVENT_PURSUE:
                 Talk(FLAME_LEVIATHAN_SAY_PURSUE);
                 me->CastSpell(me, SPELL_PURSUED, false);
@@ -577,7 +568,6 @@ void boss_flame_leviathan::ScheduleEvents()
     events.RescheduleEvent(EVENT_VENT, 20s);
     events.RescheduleEvent(EVENT_SPEED, 15s);
     events.RescheduleEvent(EVENT_SOUND_BEGINNING, 10s);
-    events.RescheduleEvent(EVENT_POSITION_CHECK, 5s);
 
     events.RescheduleEvent(EVENT_PURSUE, 0ms);
 }
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/instance_ulduar.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/instance_ulduar.cpp
index 80b0a0a481..5712fe72f8 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/instance_ulduar.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/instance_ulduar.cpp
@@ -164,6 +164,11 @@ ObjectData const gameobjectData[] =
     { 0,                                0                               }
 };
 
+BossBoundaryData const boundaries =
+{
+    { BOSS_LEVIATHAN, new RectangleBoundary(130.0f, 450.0f, -170.0f, 110.0f) },
+};
+
 class instance_ulduar : public InstanceMapScript
 {
 public:
@@ -183,6 +188,7 @@ public:
             SetPersistentDataCount(MAX_PERSISTENT_DATA);
             LoadDoorData(doorData);
             LoadObjectData(creatureData, gameobjectData);
+            LoadBossBoundaries(boundaries);
             Initialize();
         };