diff --git a/apps/openmw-mp/Script/Functions/Actors.cpp b/apps/openmw-mp/Script/Functions/Actors.cpp
index 8dbe8b6ba..c236e992e 100644
--- a/apps/openmw-mp/Script/Functions/Actors.cpp
+++ b/apps/openmw-mp/Script/Functions/Actors.cpp
@@ -489,10 +489,11 @@ void ActorFunctions::UnequipActorItem(unsigned short slot) noexcept
     ActorFunctions::EquipActorItem(slot, "", 0, -1, -1);
 }
 
-void ActorFunctions::AddActorSpellActive(const char* spellId, const char* displayName) noexcept
+void ActorFunctions::AddActorSpellActive(const char* spellId, const char* displayName, bool stackingState) noexcept
 {
     mwmp::ActiveSpell spell;
     spell.id = spellId;
+    spell.isStackingSpell = stackingState;
     spell.params.mDisplayName = displayName;
     spell.params.mEffects = storedActorActiveEffects;
 
diff --git a/apps/openmw-mp/Script/Functions/Actors.hpp b/apps/openmw-mp/Script/Functions/Actors.hpp
index 80ff88e47..0b492476f 100644
--- a/apps/openmw-mp/Script/Functions/Actors.hpp
+++ b/apps/openmw-mp/Script/Functions/Actors.hpp
@@ -879,9 +879,10 @@ public:
     *
     * \param spellId The spellId of the spell.
     * \param displayName The displayName of the spell.
+    * \param stackingState Whether the spell should stack with other instances of itself.
     * \return void
     */
-    static void AddActorSpellActive(const char* spellId, const char* displayName) noexcept;
+    static void AddActorSpellActive(const char* spellId, const char* displayName, bool stackingState) noexcept;
 
     /**
     * \brief Add a new effect to the next active spell that will be added to the temporary actor
diff --git a/apps/openmw-mp/Script/Functions/Spells.cpp b/apps/openmw-mp/Script/Functions/Spells.cpp
index a78d035c5..4fd9c1754 100644
--- a/apps/openmw-mp/Script/Functions/Spells.cpp
+++ b/apps/openmw-mp/Script/Functions/Spells.cpp
@@ -101,13 +101,14 @@ void SpellFunctions::AddSpell(unsigned short pid, const char* spellId) noexcept
     player->spellbookChanges.spells.push_back(spell);
 }
 
-void SpellFunctions::AddSpellActive(unsigned short pid, const char* spellId, const char* displayName) noexcept
+void SpellFunctions::AddSpellActive(unsigned short pid, const char* spellId, const char* displayName, bool stackingState) noexcept
 {
     Player* player;
     GET_PLAYER(pid, player, );
 
     mwmp::ActiveSpell spell;
     spell.id = spellId;
+    spell.isStackingSpell = stackingState;
     spell.params.mDisplayName = displayName;
     spell.params.mEffects = storedActiveEffects;
 
diff --git a/apps/openmw-mp/Script/Functions/Spells.hpp b/apps/openmw-mp/Script/Functions/Spells.hpp
index f72e77983..869b7e720 100644
--- a/apps/openmw-mp/Script/Functions/Spells.hpp
+++ b/apps/openmw-mp/Script/Functions/Spells.hpp
@@ -155,9 +155,10 @@ public:
     * \param pid The player ID whose spells active changes should be used.
     * \param spellId The spellId of the spell.
     * \param displayName The displayName of the spell.
+    * \param stackingState Whether the spell should stack with other instances of itself.
     * \return void
     */
-    static void AddSpellActive(unsigned short pid, const char* spellId, const char* displayName) noexcept;
+    static void AddSpellActive(unsigned short pid, const char* spellId, const char* displayName, bool stackingState) noexcept;
 
     /**
     * \brief Add a new effect to the next active spell that will be added to a player.