diff --git a/apps/openmw/mwmechanics/spellcasting.cpp b/apps/openmw/mwmechanics/spellcasting.cpp
index c996e90d6..26480ed03 100644
--- a/apps/openmw/mwmechanics/spellcasting.cpp
+++ b/apps/openmw/mwmechanics/spellcasting.cpp
@@ -148,13 +148,17 @@ namespace MWMechanics
         return school;
     }
 
-    float getEffectResistance (short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster, const ESM::Spell* spell)
+    float getEffectResistance (short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster,
+                               const ESM::Spell* spell, const MagicEffects* effects)
     {
         const ESM::MagicEffect *magicEffect =
             MWBase::Environment::get().getWorld()->getStore().get<ESM::MagicEffect>().find (
             effectId);
 
         const MWMechanics::CreatureStats& stats = actor.getClass().getCreatureStats(actor);
+        const MWMechanics::MagicEffects* magicEffects = &stats.getMagicEffects();
+        if (effects)
+            magicEffects = effects;
 
         float resisted = 0;
         if (magicEffect->mData.mFlags & ESM::MagicEffect::Harmful)
@@ -165,9 +169,9 @@ namespace MWMechanics
 
             float resistance = 0;
             if (resistanceEffect != -1)
-                resistance += stats.getMagicEffects().get(resistanceEffect).mMagnitude;
+                resistance += magicEffects->get(resistanceEffect).mMagnitude;
             if (weaknessEffect != -1)
-                resistance -= stats.getMagicEffects().get(weaknessEffect).mMagnitude;
+                resistance -= magicEffects->get(weaknessEffect).mMagnitude;
 
 
             float willpower = stats.getAttribute(ESM::Attribute::Willpower).getModified();
@@ -204,9 +208,10 @@ namespace MWMechanics
         return resisted;
     }
 
-    float getEffectMultiplier(short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster, const ESM::Spell* spell)
+    float getEffectMultiplier(short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster,
+                              const ESM::Spell* spell, const MagicEffects* effects)
     {
-        float resistance = getEffectResistance(effectId, actor, caster, spell);
+        float resistance = getEffectResistance(effectId, actor, caster, spell, effects);
         if (resistance >= 0)
             return 1 - resistance / 100.f;
         else
@@ -261,6 +266,13 @@ namespace MWMechanics
         bool firstAppliedEffect = true;
         bool anyHarmfulEffect = false;
 
+        // HACK: cache target's magic effects here, and add any applied effects to it. Use the cached effects for determining resistance.
+        // This is required for Weakness effects in a spell to apply to any subsequent effects in the spell.
+        // Otherwise, they'd only apply after the whole spell was added.
+        MagicEffects targetEffects;
+        if (target.getClass().isActor())
+            targetEffects += target.getClass().getCreatureStats(target).getMagicEffects();
+
         bool castByPlayer = (!caster.isEmpty() && caster.getRefData().getHandle() == "player");
 
         for (std::vector<ESM::ENAMstruct>::const_iterator effectIt (effects.mList.begin());
@@ -346,8 +358,7 @@ namespace MWMechanics
                 // Try resisting
                 if (magnitudeMult > 0 && target.getClass().isActor())
                 {
-
-                    magnitudeMult = MWMechanics::getEffectMultiplier(effectIt->mEffectID, target, caster, spell);
+                    magnitudeMult = MWMechanics::getEffectMultiplier(effectIt->mEffectID, target, caster, spell, &targetEffects);
                     if (magnitudeMult == 0)
                     {
                         // Fully resisted, show message
@@ -375,6 +386,8 @@ namespace MWMechanics
                     effect.mDuration = effectIt->mDuration;
                     effect.mMagnitude = magnitude;
 
+                    targetEffects.add(MWMechanics::EffectKey(*effectIt), MWMechanics::EffectParam(effect.mMagnitude));
+
                     appliedLastingEffects.push_back(effect);
 
                     // For absorb effects, also apply the effect to the caster - but with a negative
diff --git a/apps/openmw/mwmechanics/spellcasting.hpp b/apps/openmw/mwmechanics/spellcasting.hpp
index dce4b792e..821d7ae0e 100644
--- a/apps/openmw/mwmechanics/spellcasting.hpp
+++ b/apps/openmw/mwmechanics/spellcasting.hpp
@@ -18,6 +18,7 @@ namespace ESM
 namespace MWMechanics
 {
     class EffectKey;
+    class MagicEffects;
 
     ESM::Skill::SkillEnum spellSchoolToSkill(int school);
 
@@ -35,9 +36,13 @@ namespace MWMechanics
     int getSpellSchool(const ESM::Spell* spell, const MWWorld::Ptr& actor);
 
     /// @return >=100 for fully resisted. can also return negative value for damage amplification.
-    float getEffectResistance (short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster, const ESM::Spell* spell = NULL);
+    /// @param effects Override the actor's current magicEffects. Useful if there are effects currently
+    ///                being applied (but not applied yet) that should also be considered.
+    float getEffectResistance (short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster,
+                               const ESM::Spell* spell = NULL, const MagicEffects* effects = NULL);
 
-    float getEffectMultiplier(short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster, const ESM::Spell* spell = NULL);
+    float getEffectMultiplier(short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster,
+                              const ESM::Spell* spell = NULL, const MagicEffects* effects = NULL);
 
     class CastSpell
     {