diff --git a/CHANGELOG.md b/CHANGELOG.md
index b37fed31fd..58d111dd01 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
     Bug #3246: ESSImporter: Most NPCs are dead on save load
     Bug #3514: Editing a reference's position after loading an esp file makes the reference disappear
     Bug #3737: Scripts from The Underground 2 .esp do not play (all patched versions)
+    Bug #3792: 1 frame late magicka recalc breaks early scripted magicka reactions to Intelligence change
     Bug #3846: Strings starting with "-" fail to compile if not enclosed in quotes
     Bug #3905: Great House Dagoth issues
     Bug #4203: Resurrecting an actor should close the loot GUI
diff --git a/apps/openmw/mwclass/creature.cpp b/apps/openmw/mwclass/creature.cpp
index a9b1f461ca..4ca5b37cf8 100644
--- a/apps/openmw/mwclass/creature.cpp
+++ b/apps/openmw/mwclass/creature.cpp
@@ -112,7 +112,10 @@ namespace MWClass
     {
         if (!ptr.getRefData().getCustomData())
         {
-            std::unique_ptr<CreatureCustomData> data (new CreatureCustomData);
+            auto tempData = std::make_unique<CreatureCustomData>();
+            CreatureCustomData* data = tempData.get();
+            MWMechanics::CreatureCustomDataResetter resetter(ptr);
+            ptr.getRefData().setCustomData(std::move(tempData));
 
             MWWorld::LiveCellRef<ESM::Creature> *ref = ptr.get<ESM::Creature>();
 
@@ -156,10 +159,7 @@ namespace MWClass
 
             data->mCreatureStats.setGoldPool(ref->mBase->mData.mGold);
 
-            data->mCreatureStats.setNeedRecalcDynamicStats(false);
-
-            // store
-            ptr.getRefData().setCustomData(std::move(data));
+            resetter.mPtr = {};
 
             getContainerStore(ptr).fill(ref->mBase->mInventory, ptr.getCellRef().getRefId());
 
diff --git a/apps/openmw/mwclass/npc.cpp b/apps/openmw/mwclass/npc.cpp
index becfb8719f..b8df6747b3 100644
--- a/apps/openmw/mwclass/npc.cpp
+++ b/apps/openmw/mwclass/npc.cpp
@@ -303,7 +303,11 @@ namespace MWClass
     {
         if (!ptr.getRefData().getCustomData())
         {
-            std::unique_ptr<NpcCustomData> data(new NpcCustomData);
+            bool recalculate = false;
+            auto tempData = std::make_unique<NpcCustomData>();
+            NpcCustomData* data = tempData.get();
+            MWMechanics::CreatureCustomDataResetter resetter(ptr);
+            ptr.getRefData().setCustomData(std::move(tempData));
 
             MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
 
@@ -334,8 +338,6 @@ namespace MWClass
                 data->mNpcStats.setLevel(ref->mBase->mNpdt.mLevel);
                 data->mNpcStats.setBaseDisposition(ref->mBase->mNpdt.mDisposition);
                 data->mNpcStats.setReputation(ref->mBase->mNpdt.mReputation);
-
-                data->mNpcStats.setNeedRecalcDynamicStats(false);
             }
             else
             {
@@ -351,7 +353,7 @@ namespace MWClass
                 autoCalculateAttributes(ref->mBase, data->mNpcStats);
                 autoCalculateSkills(ref->mBase, data->mNpcStats, ptr, spellsInitialised);
 
-                data->mNpcStats.setNeedRecalcDynamicStats(true);
+                recalculate = true;
             }
 
             // Persistent actors with 0 health do not play death animation
@@ -387,7 +389,9 @@ namespace MWClass
             data->mNpcStats.setGoldPool(gold);
 
             // store
-            ptr.getRefData().setCustomData(std::move(data));
+            resetter.mPtr = {};
+            if(recalculate)
+                data->mNpcStats.recalculateMagicka();
 
             // inventory
             // setting ownership is used to make the NPC auto-equip his initial equipment only, and not bartered items
diff --git a/apps/openmw/mwmechanics/actors.cpp b/apps/openmw/mwmechanics/actors.cpp
index d85946dbd5..0af65844f9 100644
--- a/apps/openmw/mwmechanics/actors.cpp
+++ b/apps/openmw/mwmechanics/actors.cpp
@@ -240,10 +240,7 @@ namespace MWMechanics
     {
         // magic effects
         adjustMagicEffects (ptr, duration);
-        if (ptr.getClass().getCreatureStats(ptr).needToRecalcDynamicStats())
-            calculateDynamicStats (ptr);
 
-        calculateCreatureStatModifiers (ptr, duration);
         // fatigue restoration
         calculateRestoration(ptr, duration);
     }
@@ -654,29 +651,6 @@ namespace MWMechanics
             updateSummons(creature, mTimerDisposeSummonsCorpses == 0.f);
     }
 
-    void Actors::calculateDynamicStats (const MWWorld::Ptr& ptr)
-    {
-        CreatureStats& creatureStats = ptr.getClass().getCreatureStats (ptr);
-
-        float intelligence = creatureStats.getAttribute(ESM::Attribute::Intelligence).getModified();
-
-        float base = 1.f;
-        if (ptr == getPlayer())
-            base = MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fPCbaseMagickaMult")->mValue.getFloat();
-        else
-            base = MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fNPCbaseMagickaMult")->mValue.getFloat();
-
-        double magickaFactor = base +
-            creatureStats.getMagicEffects().get (EffectKey (ESM::MagicEffect::FortifyMaximumMagicka)).getMagnitude() * 0.1;
-
-        DynamicStat<float> magicka = creatureStats.getMagicka();
-        float diff = (static_cast<int>(magickaFactor*intelligence)) - magicka.getBase();
-        float currentToBaseRatio = magicka.getBase() > 0 ? magicka.getCurrent() / magicka.getBase() : 0;
-        magicka.setModified(magicka.getModified() + diff, 0);
-        magicka.setCurrent(magicka.getBase() * currentToBaseRatio, false, true);
-        creatureStats.setMagicka(magicka);
-    }
-
     void Actors::restoreDynamicStats (const MWWorld::Ptr& ptr, double hours, bool sleep)
     {
         MWMechanics::CreatureStats& stats = ptr.getClass().getCreatureStats (ptr);
@@ -771,14 +745,6 @@ namespace MWMechanics
         stats.setFatigue (fatigue);
     }
 
-    void Actors::calculateCreatureStatModifiers (const MWWorld::Ptr& ptr, float duration)
-    {
-        CreatureStats &creatureStats = ptr.getClass().getCreatureStats(ptr);
-
-        if (creatureStats.needToRecalcDynamicStats())
-            calculateDynamicStats(ptr);
-    }
-
     bool Actors::isAttackPreparing(const MWWorld::Ptr& ptr)
     {
         PtrActorMap::iterator it = mActors.find(ptr);
@@ -1711,10 +1677,6 @@ namespace MWMechanics
                 if (iter->first.getType() == ESM::Creature::sRecordId)
                     soulTrap(iter->first);
 
-                // Magic effects will be reset later, and the magic effect that could kill the actor
-                // needs to be determined now
-                calculateCreatureStatModifiers(iter->first, 0);
-
                 if (cls.isEssential(iter->first))
                     MWBase::Environment::get().getWindowManager()->messageBox("#{sKilledEssential}");
             }
@@ -1730,8 +1692,6 @@ namespace MWMechanics
                 // Make sure spell effects are removed
                 purgeSpellEffects(stats.getActorId());
 
-                // Reset dynamic stats, attributes and skills
-                calculateCreatureStatModifiers(iter->first, 0);
                 stats.getMagicEffects().add(ESM::MagicEffect::Vampirism, vampirism);
 
                 if (isPlayer)
@@ -1816,10 +1776,6 @@ namespace MWMechanics
                 continue;
 
             adjustMagicEffects (iter->first, duration);
-            if (iter->first.getClass().getCreatureStats(iter->first).needToRecalcDynamicStats())
-                calculateDynamicStats (iter->first);
-
-            calculateCreatureStatModifiers (iter->first, duration);
 
             MWRender::Animation* animation = MWBase::Environment::get().getWorld()->getAnimation(iter->first);
             if (animation)
@@ -2209,7 +2165,6 @@ namespace MWMechanics
     void Actors::updateMagicEffects(const MWWorld::Ptr &ptr)
     {
         adjustMagicEffects(ptr, 0.f);
-        calculateCreatureStatModifiers(ptr, 0.f);
     }
 
     bool Actors::isReadyToBlock(const MWWorld::Ptr &ptr) const
diff --git a/apps/openmw/mwmechanics/actors.hpp b/apps/openmw/mwmechanics/actors.hpp
index 9950a591ab..7d44fd06cd 100644
--- a/apps/openmw/mwmechanics/actors.hpp
+++ b/apps/openmw/mwmechanics/actors.hpp
@@ -43,10 +43,6 @@ namespace MWMechanics
 
             void adjustMagicEffects (const MWWorld::Ptr& creature, float duration);
 
-            void calculateDynamicStats (const MWWorld::Ptr& ptr);
-
-            void calculateCreatureStatModifiers (const MWWorld::Ptr& ptr, float duration);
-
             void calculateRestoration (const MWWorld::Ptr& ptr, float duration);
 
             void updateDrowning (const MWWorld::Ptr& ptr, float duration, bool isKnockedOut, bool isPlayer);
diff --git a/apps/openmw/mwmechanics/actorutil.cpp b/apps/openmw/mwmechanics/actorutil.cpp
index 04cbb8e9f5..4a587dd662 100644
--- a/apps/openmw/mwmechanics/actorutil.cpp
+++ b/apps/openmw/mwmechanics/actorutil.cpp
@@ -29,4 +29,12 @@ namespace MWMechanics
         const MWMechanics::MagicEffects& effects = actor.getClass().getCreatureStats(actor).getMagicEffects();
         return effects.get(ESM::MagicEffect::WaterWalking).getMagnitude() > 0;
     }
+
+    CreatureCustomDataResetter::CreatureCustomDataResetter(const MWWorld::Ptr& ptr) : mPtr(ptr) {}
+
+    CreatureCustomDataResetter::~CreatureCustomDataResetter()
+    {
+        if(!mPtr.isEmpty())
+            mPtr.getRefData().setCustomData({});
+    }
 }
diff --git a/apps/openmw/mwmechanics/actorutil.hpp b/apps/openmw/mwmechanics/actorutil.hpp
index a226fc9cb6..a66d8866bf 100644
--- a/apps/openmw/mwmechanics/actorutil.hpp
+++ b/apps/openmw/mwmechanics/actorutil.hpp
@@ -86,6 +86,14 @@ namespace MWMechanics
     template void modifyBaseInventory<ESM::Creature>(const std::string& actorId, const std::string& itemId, int amount);
     template void modifyBaseInventory<ESM::NPC>(const std::string& actorId, const std::string& itemId, int amount);
     template void modifyBaseInventory<ESM::Container>(const std::string& containerId, const std::string& itemId, int amount);
+
+    struct CreatureCustomDataResetter
+    {
+        MWWorld::Ptr mPtr;
+
+        CreatureCustomDataResetter(const MWWorld::Ptr& ptr);
+        ~CreatureCustomDataResetter();
+    };
 }
 
 #endif
diff --git a/apps/openmw/mwmechanics/creaturestats.cpp b/apps/openmw/mwmechanics/creaturestats.cpp
index 8ca6e8b766..6710dcd734 100644
--- a/apps/openmw/mwmechanics/creaturestats.cpp
+++ b/apps/openmw/mwmechanics/creaturestats.cpp
@@ -7,6 +7,7 @@
 #include <components/esm/esmreader.hpp>
 #include <components/esm/esmwriter.hpp>
 
+#include "../mwworld/class.hpp"
 #include "../mwworld/esmstore.hpp"
 #include "../mwworld/player.hpp"
 
@@ -22,7 +23,7 @@ namespace MWMechanics
           mTalkedTo (false), mAlarmed (false), mAttacked (false),
           mKnockdown(false), mKnockdownOneFrame(false), mKnockdownOverOneFrame(false),
           mHitRecovery(false), mBlock(false), mMovementFlags(0),
-          mFallHeight(0), mRecalcMagicka(false), mLastRestock(0,0), mGoldPool(0), mActorId(-1), mHitAttemptActorId(-1),
+          mFallHeight(0), mLastRestock(0,0), mGoldPool(0), mActorId(-1), mHitAttemptActorId(-1),
           mDeathAnimation(-1), mTimeOfDeath(), mSideMovementAngle(0), mLevel (0)
     {
         for (int i=0; i<4; ++i)
@@ -146,7 +147,7 @@ namespace MWMechanics
             mAttributes[index] = value;
 
             if (index == ESM::Attribute::Intelligence)
-                mRecalcMagicka = true;
+                recalculateMagicka();
             else if (index == ESM::Attribute::Strength ||
                      index == ESM::Attribute::Willpower ||
                      index == ESM::Attribute::Agility ||
@@ -208,11 +209,10 @@ namespace MWMechanics
 
     void CreatureStats::modifyMagicEffects(const MagicEffects &effects)
     {
-        if (effects.get(ESM::MagicEffect::FortifyMaximumMagicka).getModifier()
-                != mMagicEffects.get(ESM::MagicEffect::FortifyMaximumMagicka).getModifier())
-            mRecalcMagicka = true;
-
+        bool recalc = effects.get(ESM::MagicEffect::FortifyMaximumMagicka).getModifier() != mMagicEffects.get(ESM::MagicEffect::FortifyMaximumMagicka).getModifier();
         mMagicEffects.setModifiers(effects);
+        if(recalc)
+            recalculateMagicka();
     }
 
     void CreatureStats::setAiSetting (AiSetting index, Stat<int> value)
@@ -400,19 +400,26 @@ namespace MWMechanics
         return height;
     }
 
-    bool CreatureStats::needToRecalcDynamicStats()
+    void CreatureStats::recalculateMagicka()
     {
-         if (mRecalcMagicka)
-         {
-             mRecalcMagicka = false;
-             return true;
-         }
-         return false;
-    }
+        auto world = MWBase::Environment::get().getWorld();
+        float intelligence = getAttribute(ESM::Attribute::Intelligence).getModified();
 
-    void CreatureStats::setNeedRecalcDynamicStats(bool val)
-    {
-        mRecalcMagicka = val;
+        float base = 1.f;
+        const auto& player = world->getPlayerPtr();
+        if (this == &player.getClass().getCreatureStats(player))
+            base = world->getStore().get<ESM::GameSetting>().find("fPCbaseMagickaMult")->mValue.getFloat();
+        else
+            base = world->getStore().get<ESM::GameSetting>().find("fNPCbaseMagickaMult")->mValue.getFloat();
+
+        double magickaFactor = base + mMagicEffects.get(EffectKey(ESM::MagicEffect::FortifyMaximumMagicka)).getMagnitude() * 0.1;
+
+        DynamicStat<float> magicka = getMagicka();
+        float diff = (static_cast<int>(magickaFactor*intelligence)) - magicka.getBase();
+        float currentToBaseRatio = magicka.getBase() > 0 ? magicka.getCurrent() / magicka.getBase() : 0;
+        magicka.setModified(magicka.getModified() + diff, 0);
+        magicka.setCurrent(magicka.getBase() * currentToBaseRatio, false, true);
+        setMagicka(magicka);
     }
 
     void CreatureStats::setKnockedDown(bool value)
@@ -532,7 +539,6 @@ namespace MWMechanics
         state.mFallHeight = mFallHeight; // TODO: vertical velocity (move from PhysicActor to CreatureStats?)
         state.mLastHitObject = mLastHitObject;
         state.mLastHitAttemptObject = mLastHitAttemptObject;
-        state.mRecalcDynamicStats = mRecalcMagicka;
         state.mDrawState = mDrawState;
         state.mLevel = mLevel;
         state.mActorId = mActorId;
@@ -586,7 +592,6 @@ namespace MWMechanics
         mFallHeight = state.mFallHeight;
         mLastHitObject = state.mLastHitObject;
         mLastHitAttemptObject = state.mLastHitAttemptObject;
-        mRecalcMagicka = state.mRecalcDynamicStats;
         mDrawState = DrawState_(state.mDrawState);
         mLevel = state.mLevel;
         mActorId = state.mActorId;
@@ -627,6 +632,8 @@ namespace MWMechanics
         if (state.mHasAiSettings)
             for (int i=0; i<4; ++i)
                 mAiSettings[i].readState(state.mAiSettings[i]);
+        if(state.mRecalcDynamicStats)
+            recalculateMagicka();
     }
 
     void CreatureStats::setLastRestockTime(MWWorld::TimeStamp tradeTime)
diff --git a/apps/openmw/mwmechanics/creaturestats.hpp b/apps/openmw/mwmechanics/creaturestats.hpp
index d234d14486..e5c4f6fa41 100644
--- a/apps/openmw/mwmechanics/creaturestats.hpp
+++ b/apps/openmw/mwmechanics/creaturestats.hpp
@@ -65,8 +65,6 @@ namespace MWMechanics
         std::string mLastHitObject; // The last object to hit this actor
         std::string mLastHitAttemptObject; // The last object to attempt to hit this actor
 
-        bool mRecalcMagicka;
-
         // For merchants: the last time items were restocked and gold pool refilled.
         MWWorld::TimeStamp mLastRestock;
 
@@ -103,8 +101,7 @@ namespace MWMechanics
         DrawState_ getDrawState() const;
         void setDrawState(DrawState_ state);
 
-        bool needToRecalcDynamicStats();
-        void setNeedRecalcDynamicStats(bool val);
+        void recalculateMagicka();
 
         float getFallHeight() const;
         void addToFallHeight(float height);
diff --git a/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp b/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
index 149056e605..e01ed3c425 100644
--- a/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
+++ b/apps/openmw/mwmechanics/mechanicsmanagerimp.cpp
@@ -77,7 +77,7 @@ namespace MWMechanics
         MWMechanics::CreatureStats& creatureStats = ptr.getClass().getCreatureStats (ptr);
         MWMechanics::NpcStats& npcStats = ptr.getClass().getNpcStats (ptr);
 
-        npcStats.setNeedRecalcDynamicStats(true);
+        npcStats.recalculateMagicka();
 
         const ESM::NPC *player = ptr.get<ESM::NPC>()->mBase;
 
@@ -222,7 +222,6 @@ namespace MWMechanics
 
         // forced update and current value adjustments
         mActors.updateActor (ptr, 0);
-        mActors.updateActor (ptr, 0);
 
         for (int i=0; i<3; ++i)
         {
diff --git a/apps/openmw/mwmechanics/spelleffects.cpp b/apps/openmw/mwmechanics/spelleffects.cpp
index 0e67f06ba2..d9e32b8b9f 100644
--- a/apps/openmw/mwmechanics/spelleffects.cpp
+++ b/apps/openmw/mwmechanics/spelleffects.cpp
@@ -279,7 +279,7 @@ namespace
 namespace MWMechanics
 {
 
-void applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, const ActiveSpells::ActiveSpellParams& spellParams, ESM::ActiveEffect& effect, bool& invalid, bool& receivedMagicDamage)
+void applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, const ActiveSpells::ActiveSpellParams& spellParams, ESM::ActiveEffect& effect, bool& invalid, bool& receivedMagicDamage, bool& recalculateMagicka)
 {
     const auto world = MWBase::Environment::get().getWorld();
     bool godmode = target == getPlayer() && world->getGodModeState();
@@ -609,7 +609,7 @@ void applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, co
                 fortifySkill(target, effect, effect.mMagnitude);
             break;
         case ESM::MagicEffect::FortifyMaximumMagicka:
-            target.getClass().getCreatureStats(target).setNeedRecalcDynamicStats(true);
+            recalculateMagicka = true;
             break;
         case ESM::MagicEffect::AbsorbHealth:
         case ESM::MagicEffect::AbsorbMagicka:
@@ -687,13 +687,14 @@ bool applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, Ac
     const auto world = MWBase::Environment::get().getWorld();
     bool invalid = false;
     bool receivedMagicDamage = false;
+    bool recalculateMagicka = false;
     if(effect.mEffectId == ESM::MagicEffect::Corprus && spellParams.shouldWorsen())
     {
         spellParams.worsen();
         for(auto& otherEffect : spellParams.getEffects())
         {
             if(isCorprusEffect(otherEffect))
-                applyMagicEffect(target, caster, spellParams, otherEffect, invalid, receivedMagicDamage);
+                applyMagicEffect(target, caster, spellParams, otherEffect, invalid, receivedMagicDamage, recalculateMagicka);
         }
         if(target == getPlayer())
             MWBase::Environment::get().getWindowManager()->messageBox("#{sMagicCorprusWorsens}");
@@ -815,7 +816,7 @@ bool applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, Ac
         if(effect.mEffectId == ESM::MagicEffect::Corprus)
             spellParams.worsen();
         else
-            applyMagicEffect(target, caster, spellParams, effect, invalid, receivedMagicDamage);
+            applyMagicEffect(target, caster, spellParams, effect, invalid, receivedMagicDamage, recalculateMagicka);
         effect.mMagnitude = magnitude;
         magnitudes.add(EffectKey(effect.mEffectId, effect.mArg), EffectParam(effect.mMagnitude - oldMagnitude));
     }
@@ -832,6 +833,8 @@ bool applyMagicEffect(const MWWorld::Ptr& target, const MWWorld::Ptr& caster, Ac
         effect.mFlags |= ESM::ActiveEffect::Flag_Applied | ESM::ActiveEffect::Flag_Remove;
     if (receivedMagicDamage && target == getPlayer())
         MWBase::Environment::get().getWindowManager()->activateHitOverlay(false);
+    if(recalculateMagicka)
+        target.getClass().getCreatureStats(target).recalculateMagicka();
     return false;
 }
 
@@ -981,7 +984,7 @@ void removeMagicEffect(const MWWorld::Ptr& target, ActiveSpells::ActiveSpellPara
                 fortifySkill(target, effect, -effect.mMagnitude);
             break;
         case ESM::MagicEffect::FortifyMaximumMagicka:
-            target.getClass().getCreatureStats(target).setNeedRecalcDynamicStats(true);
+            target.getClass().getCreatureStats(target).recalculateMagicka();
             break;
         case ESM::MagicEffect::AbsorbAttribute:
             {