diff --git a/apps/openmw/mwworld/inventorystore.cpp b/apps/openmw/mwworld/inventorystore.cpp
index 0f9b2380c..b82b798d1 100644
--- a/apps/openmw/mwworld/inventorystore.cpp
+++ b/apps/openmw/mwworld/inventorystore.cpp
@@ -742,7 +742,7 @@ void MWWorld::InventoryStore::clear()
     ContainerStore::clear();
 }
 
-bool MWWorld::InventoryStore::isEquipped(const MWWorld::Ptr &item)
+bool MWWorld::InventoryStore::isEquipped(const MWWorld::ConstPtr &item)
 {
     for (int i=0; i < MWWorld::InventoryStore::Slots; ++i)
     {
diff --git a/apps/openmw/mwworld/inventorystore.hpp b/apps/openmw/mwworld/inventorystore.hpp
index 1e03746ff..28c44bcec 100644
--- a/apps/openmw/mwworld/inventorystore.hpp
+++ b/apps/openmw/mwworld/inventorystore.hpp
@@ -141,7 +141,7 @@ namespace MWWorld
             void equip (int slot, const ContainerStoreIterator& iterator, const Ptr& actor);
             ///< \warning \a iterator can not be an end()-iterator, use unequip function instead
 
-            bool isEquipped(const MWWorld::Ptr& item);
+            bool isEquipped(const MWWorld::ConstPtr& item);
             ///< Utility function, returns true if the given item is equipped in any slot
 
             void setSelectedEnchantItem(const ContainerStoreIterator& iterator);