diff --git a/lib/BattleState.cpp b/lib/BattleState.cpp
index 642fdeb94..69017b115 100644
--- a/lib/BattleState.cpp
+++ b/lib/BattleState.cpp
@@ -168,7 +168,7 @@ ui32 CBattleInfoCallback::calculateHealedHP(const CGHeroInstance * caster, const
 		healedHealth = (caster->getPrimSkillLevel(PrimarySkill::SPELL_POWER) + sacrificedStack->MaxHealth() + spell->getPower(caster->getSpellSchoolLevel(spell))) * sacrificedStack->count;
 	else
 		healedHealth = caster->getPrimSkillLevel(PrimarySkill::SPELL_POWER) * spell->power + spell->getPower(caster->getSpellSchoolLevel(spell)); //???
-	healedHealth = calculateSpellBonus(healedHealth, spell, caster, stack);
+	healedHealth = spell->calculateBonus(healedHealth, caster, stack);
 	return std::min<ui32>(healedHealth, stack->MaxHealth() - stack->firstHPleft + (resurrect ? stack->baseAmount * stack->MaxHealth() : 0));
 }
 //Archangel
diff --git a/lib/CBattleCallback.cpp b/lib/CBattleCallback.cpp
index c0a40825d..185337efa 100644
--- a/lib/CBattleCallback.cpp
+++ b/lib/CBattleCallback.cpp
@@ -1647,8 +1647,8 @@ ESpellCastProblem::ESpellCastProblem CBattleInfoCallback::battleStackIsImmune(co
 		//TODO: what with other creatures casting hypnotize, Faerie Dragons style?
 		ui64 subjectHealth = (subject->count - 1) * subject->MaxHealth() + subject->firstHPleft;
 		//apply 'damage' bonus for hypnotize, including hero specialty
-		ui64 maxHealth = calculateSpellBonus (caster->getPrimSkillLevel(PrimarySkill::SPELL_POWER)
-			* spell->power + spell->getPower(caster->getSpellSchoolLevel(spell)), spell, caster, subject);
+		ui64 maxHealth = spell->calculateBonus (caster->getPrimSkillLevel(PrimarySkill::SPELL_POWER)
+			* spell->power + spell->getPower(caster->getSpellSchoolLevel(spell)), caster, subject);
 		if (subjectHealth > maxHealth)
 			return ESpellCastProblem::STACK_IMMUNE_TO_SPELL;
 	}	
@@ -1945,30 +1945,6 @@ ESpellCastProblem::ESpellCastProblem CBattleInfoCallback::battleCanCastThisSpell
 		return battleIsImmune(nullptr, spell, mode, dest);
 }
 
-ui32 CBattleInfoCallback::calculateSpellBonus(ui32 baseDamage, const CSpell * sp, const CGHeroInstance * caster, const CStack * affectedCreature) const
-{
-	ui32 ret = baseDamage;
-	//applying sorcery secondary skill
-	if(caster)
-	{
-		ret *= (100.0 + caster->valOfBonuses(Bonus::SECONDARY_SKILL_PREMY, SecondarySkill::SORCERY)) / 100.0;
-		ret *= (100.0 + caster->valOfBonuses(Bonus::SPELL_DAMAGE) + caster->valOfBonuses(Bonus::SPECIFIC_SPELL_DAMAGE, sp->id.toEnum())) / 100.0;
-
-		if(sp->air)
-			ret *= (100.0 + caster->valOfBonuses(Bonus::AIR_SPELL_DMG_PREMY)) / 100.0;
-		else if(sp->fire) //only one type of bonus for Magic Arrow
-			ret *= (100.0 + caster->valOfBonuses(Bonus::FIRE_SPELL_DMG_PREMY)) / 100.0;
-		else if(sp->water)
-			ret *= (100.0 + caster->valOfBonuses(Bonus::WATER_SPELL_DMG_PREMY)) / 100.0;
-		else if(sp->earth)
-			ret *= (100.0 + caster->valOfBonuses(Bonus::EARTH_SPELL_DMG_PREMY)) / 100.0;
-
-		if (affectedCreature && affectedCreature->getCreature()->level) //Hero specials like Solmyr, Deemer
-			ret *= (100. + ((caster->valOfBonuses(Bonus::SPECIAL_SPELL_LEV, sp->id.toEnum()) * caster->level) / affectedCreature->getCreature()->level)) / 100.0;
-	}
-	return ret;
-}
-
 ui32 CBattleInfoCallback::calculateSpellDmg( const CSpell * sp, const CGHeroInstance * caster, const CStack * affectedCreature, int spellSchoolLevel, int usedSpellPower ) const
 {
 	ui32 ret = 0; //value to return
@@ -2018,7 +1994,7 @@ ui32 CBattleInfoCallback::calculateSpellDmg( const CSpell * sp, const CGHeroInst
 			ret /= 100;
 		}
 	}
-	ret = calculateSpellBonus(ret, sp, caster, affectedCreature);
+	ret = sp->calculateBonus(ret, caster, affectedCreature);
 	return ret;
 }
 
diff --git a/lib/CBattleCallback.h b/lib/CBattleCallback.h
index 7ab326620..5d8a653e5 100644
--- a/lib/CBattleCallback.h
+++ b/lib/CBattleCallback.h
@@ -281,7 +281,6 @@ public:
 	ESpellCastProblem::ESpellCastProblem battleCanCastThisSpellHere(PlayerColor player, const CSpell * spell, ECastingMode::ECastingMode mode, BattleHex dest) const; //checks if given player can cast given spell at given tile in given mode
 	ESpellCastProblem::ESpellCastProblem battleCanCreatureCastThisSpell(const CSpell * spell, BattleHex destination) const; //determines if creature can cast a spell here
 	std::vector<BattleHex> battleGetPossibleTargets(PlayerColor player, const CSpell *spell) const;
-	ui32 calculateSpellBonus(ui32 baseDamage, const CSpell * sp, const CGHeroInstance * caster, const CStack * affectedCreature) const;
 	ui32 calculateSpellDmg(const CSpell * sp, const CGHeroInstance * caster, const CStack * affectedCreature, int spellSchoolLevel, int usedSpellPower) const; //calculates damage inflicted by spell
 	ui32 calculateHealedHP(const CGHeroInstance * caster, const CSpell * spell, const CStack * stack, const CStack * sacrificedStack = nullptr) const; //Sacrifice
 	ui32 calculateHealedHP(int healedHealth, const CSpell * spell, const CStack * stack) const; //for Archangel
diff --git a/lib/CSpellHandler.cpp b/lib/CSpellHandler.cpp
index 5245e2836..f2e4c7171 100644
--- a/lib/CSpellHandler.cpp
+++ b/lib/CSpellHandler.cpp
@@ -297,6 +297,30 @@ const CSpell::LevelInfo & CSpell::getLevelInfo(const int level) const
 	return levels.at(level);
 }
 
+ui32 CSpell::calculateBonus(ui32 baseDamage, const CGHeroInstance* caster, const CStack* affectedCreature) const
+{
+	ui32 ret = baseDamage;
+	//applying sorcery secondary skill
+	if(caster)
+	{
+		ret *= (100.0 + caster->valOfBonuses(Bonus::SECONDARY_SKILL_PREMY, SecondarySkill::SORCERY)) / 100.0;
+		ret *= (100.0 + caster->valOfBonuses(Bonus::SPELL_DAMAGE) + caster->valOfBonuses(Bonus::SPECIFIC_SPELL_DAMAGE, id.toEnum())) / 100.0;
+
+		if(air)
+			ret *= (100.0 + caster->valOfBonuses(Bonus::AIR_SPELL_DMG_PREMY)) / 100.0;
+		else if(fire) //only one type of bonus for Magic Arrow
+			ret *= (100.0 + caster->valOfBonuses(Bonus::FIRE_SPELL_DMG_PREMY)) / 100.0;
+		else if(water)
+			ret *= (100.0 + caster->valOfBonuses(Bonus::WATER_SPELL_DMG_PREMY)) / 100.0;
+		else if(earth)
+			ret *= (100.0 + caster->valOfBonuses(Bonus::EARTH_SPELL_DMG_PREMY)) / 100.0;
+
+		if (affectedCreature && affectedCreature->getCreature()->level) //Hero specials like Solmyr, Deemer
+			ret *= (100. + ((caster->valOfBonuses(Bonus::SPECIAL_SPELL_LEV, id.toEnum()) * caster->level) / affectedCreature->getCreature()->level)) / 100.0;
+	}
+	return ret;	
+}
+
 
 std::vector<BattleHex> CSpell::rangeInHexes(BattleHex centralHex, ui8 schoolLvl, ui8 side, bool *outDroppedHexes) const
 {
diff --git a/lib/CSpellHandler.h b/lib/CSpellHandler.h
index b72626659..35472f7ff 100644
--- a/lib/CSpellHandler.h
+++ b/lib/CSpellHandler.h
@@ -127,6 +127,9 @@ public:
 	
 	//checks for creature immunity / anything that prevent casting *at given hex* - doesn't take into acount general problems such as not having spellbook or mana points etc.
 	ESpellCastProblem::ESpellCastProblem isImmuneByStack(const CGHeroInstance * caster, ECastingMode::ECastingMode mode, const CStack * obj) const;
+	
+	//applying secondary skills
+	ui32 calculateBonus(ui32 baseDamage, const CGHeroInstance * caster, const CStack * affectedCreature) const;
 
 	si32 getCost(const int skillLevel) const;