diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index d23fc73fdb..314c20e5cb 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -6705,8 +6705,8 @@ uint32 Unit::SpellDamageBonusDone(Unit* victim, SpellInfo const* spellProto, uin
     // Default calculation
     if (DoneAdvertisedBenefit)
     {
-        if (coeff < 0)
-            coeff = CalculateDefaultCoefficient(spellProto, damagetype) * int32(stack);
+        if (coeff < 0.f)
+            coeff = CalculateDefaultCoefficient(spellProto, damagetype);
 
         if (Player* modOwner = GetSpellModOwner())
         {
@@ -6731,6 +6731,10 @@ float Unit::SpellDamagePctDone(Unit* victim, SpellInfo const* spellProto, Damage
     if (!spellProto || !victim || damagetype == DIRECT_DAMAGE)
         return 1.0f;
 
+    // Some spells don't benefit from done mods
+    if (spellProto->HasAttribute(SPELL_ATTR3_NO_DONE_BONUS))
+        return 1.0f;
+
     // Some spells don't benefit from pct done mods
     if (spellProto->HasAttribute(SPELL_ATTR6_LIMIT_PCT_DAMAGE_MODS))
         return 1.0f;
@@ -7498,7 +7502,7 @@ uint32 Unit::SpellHealingBonusDone(Unit* victim, SpellInfo const* spellProto, ui
     if (DoneAdvertisedBenefit)
     {
         if (coeff < 0.f)
-            coeff = CalculateDefaultCoefficient(spellProto, damagetype) * int32(stack) * 1.88f;  // As wowwiki says: C = (Cast Time / 3.5) * 1.88 (for healing spells)
+            coeff = CalculateDefaultCoefficient(spellProto, damagetype) * 1.88f;  // As wowwiki says: C = (Cast Time / 3.5) * 1.88 (for healing spells)
 
         if (Player* modOwner = GetSpellModOwner())
         {
@@ -7985,7 +7989,7 @@ uint32 Unit::MeleeDamageBonusDone(Unit* victim, uint32 pdamage, WeaponAttackType
         // Check for table values
         if (SpellBonusEntry const* bonus = sSpellMgr->GetSpellBonusData(spellProto->Id))
         {
-            if (bonus->ap_bonus > 0)
+            if (bonus->ap_bonus > 0.f)
             {
                 float APbonus = GetTotalAttackPowerValue(attType);
                 DoneFlatBenefit += int32(bonus->ap_bonus * APbonus);
diff --git a/src/server/game/Spells/SpellEffects.cpp b/src/server/game/Spells/SpellEffects.cpp
index ebc2afd64a..e951de7388 100644
--- a/src/server/game/Spells/SpellEffects.cpp
+++ b/src/server/game/Spells/SpellEffects.cpp
@@ -392,7 +392,7 @@ void Spell::EffectSchoolDMG(SpellEffIndex effIndex)
                     case 88084: // Arcane Blast (Mirror Image)
                         // Mage Mirror Images deal 50% of the coefficient's spell power bonus as bonus damage
                         if (Unit* owner = m_caster->ToTempSummon()->GetSummoner())
-                            damage += CalculatePct(owner->SpellDamageBonusDone(unitTarget, m_spellInfo, (uint32)damage, SPELL_DIRECT_DAMAGE, effIndex), 50);
+                            damage = CalculatePct(owner->SpellDamageBonusDone(unitTarget, m_spellInfo, (uint32)damage, SPELL_DIRECT_DAMAGE, effIndex), 50);
                         break;
                 }
                 break;