diff --git a/apps/openmw/mwclass/activator.cpp b/apps/openmw/mwclass/activator.cpp
index fcf5dcfd7..799ab5311 100644
--- a/apps/openmw/mwclass/activator.cpp
+++ b/apps/openmw/mwclass/activator.cpp
@@ -120,11 +120,9 @@ namespace MWClass
     }
 
 
-    MWWorld::Ptr
-    Activator::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Activator::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Activator> *ref =
-            ptr.get<ESM::Activator>();
+        const MWWorld::LiveCellRef<ESM::Activator> *ref = ptr.get<ESM::Activator>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/activator.hpp b/apps/openmw/mwclass/activator.hpp
index 7cdd9506c..7214b86e0 100644
--- a/apps/openmw/mwclass/activator.hpp
+++ b/apps/openmw/mwclass/activator.hpp
@@ -8,8 +8,7 @@ namespace MWClass
     class Activator : public MWWorld::Class
     {
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/apparatus.cpp b/apps/openmw/mwclass/apparatus.cpp
index a90a53adb..36870997b 100644
--- a/apps/openmw/mwclass/apparatus.cpp
+++ b/apps/openmw/mwclass/apparatus.cpp
@@ -135,11 +135,9 @@ namespace MWClass
         return boost::shared_ptr<MWWorld::Action>(new MWWorld::ActionAlchemy());
     }
 
-    MWWorld::Ptr
-    Apparatus::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Apparatus::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Apparatus> *ref =
-            ptr.get<ESM::Apparatus>();
+        const MWWorld::LiveCellRef<ESM::Apparatus> *ref = ptr.get<ESM::Apparatus>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/apparatus.hpp b/apps/openmw/mwclass/apparatus.hpp
index e50a57c6a..d8176d5df 100644
--- a/apps/openmw/mwclass/apparatus.hpp
+++ b/apps/openmw/mwclass/apparatus.hpp
@@ -8,8 +8,7 @@ namespace MWClass
     class Apparatus : public MWWorld::Class
     {
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/armor.cpp b/apps/openmw/mwclass/armor.cpp
index 500664b36..d4605a195 100644
--- a/apps/openmw/mwclass/armor.cpp
+++ b/apps/openmw/mwclass/armor.cpp
@@ -365,11 +365,9 @@ namespace MWClass
         return action;
     }
 
-    MWWorld::Ptr
-    Armor::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Armor::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/armor.hpp b/apps/openmw/mwclass/armor.hpp
index 8ddd92e4d..5fd431193 100644
--- a/apps/openmw/mwclass/armor.hpp
+++ b/apps/openmw/mwclass/armor.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Armor : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/book.cpp b/apps/openmw/mwclass/book.cpp
index 25be08587..591a3cc69 100644
--- a/apps/openmw/mwclass/book.cpp
+++ b/apps/openmw/mwclass/book.cpp
@@ -173,11 +173,9 @@ namespace MWClass
         return boost::shared_ptr<MWWorld::Action>(new MWWorld::ActionRead(ptr));
     }
 
-    MWWorld::Ptr
-    Book::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Book::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Book> *ref =
-            ptr.get<ESM::Book>();
+        const MWWorld::LiveCellRef<ESM::Book> *ref = ptr.get<ESM::Book>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/book.hpp b/apps/openmw/mwclass/book.hpp
index a0b5b434e..84f744893 100644
--- a/apps/openmw/mwclass/book.hpp
+++ b/apps/openmw/mwclass/book.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Book : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/clothing.cpp b/apps/openmw/mwclass/clothing.cpp
index bf3b90941..d7a949168 100644
--- a/apps/openmw/mwclass/clothing.cpp
+++ b/apps/openmw/mwclass/clothing.cpp
@@ -258,11 +258,9 @@ namespace MWClass
         return action;
     }
 
-    MWWorld::Ptr
-    Clothing::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Clothing::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Clothing> *ref =
-            ptr.get<ESM::Clothing>();
+        const MWWorld::LiveCellRef<ESM::Clothing> *ref = ptr.get<ESM::Clothing>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/clothing.hpp b/apps/openmw/mwclass/clothing.hpp
index e513613e4..13ec2e593 100644
--- a/apps/openmw/mwclass/clothing.hpp
+++ b/apps/openmw/mwclass/clothing.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Clothing : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/container.cpp b/apps/openmw/mwclass/container.cpp
index c70228bae..03c676b9e 100644
--- a/apps/openmw/mwclass/container.cpp
+++ b/apps/openmw/mwclass/container.cpp
@@ -284,10 +284,9 @@ namespace MWClass
         return true;
     }
 
-    MWWorld::Ptr Container::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Container::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Container> *ref =
-            ptr.get<ESM::Container>();
+        const MWWorld::LiveCellRef<ESM::Container> *ref = ptr.get<ESM::Container>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/container.hpp b/apps/openmw/mwclass/container.hpp
index c6a23df6c..9b6d5d2e0 100644
--- a/apps/openmw/mwclass/container.hpp
+++ b/apps/openmw/mwclass/container.hpp
@@ -10,8 +10,7 @@ namespace MWClass
             void ensureCustomData (const MWWorld::Ptr& ptr) const;
 
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/creature.cpp b/apps/openmw/mwclass/creature.cpp
index f903144b6..38e0a826d 100644
--- a/apps/openmw/mwclass/creature.cpp
+++ b/apps/openmw/mwclass/creature.cpp
@@ -590,11 +590,9 @@ namespace MWClass
         return "";
     }
 
-    MWWorld::Ptr
-    Creature::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Creature::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Creature> *ref =
-            ptr.get<ESM::Creature>();
+        const MWWorld::LiveCellRef<ESM::Creature> *ref = ptr.get<ESM::Creature>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/creature.hpp b/apps/openmw/mwclass/creature.hpp
index 5f110e918..5076d36d0 100644
--- a/apps/openmw/mwclass/creature.hpp
+++ b/apps/openmw/mwclass/creature.hpp
@@ -14,8 +14,7 @@ namespace MWClass
     {
             void ensureCustomData (const MWWorld::Ptr& ptr) const;
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
             static int getSndGenTypeFromName(const MWWorld::Ptr &ptr, const std::string &name);
 
diff --git a/apps/openmw/mwclass/door.cpp b/apps/openmw/mwclass/door.cpp
index 3e6f2b956..f279ae3a0 100644
--- a/apps/openmw/mwclass/door.cpp
+++ b/apps/openmw/mwclass/door.cpp
@@ -299,11 +299,9 @@ namespace MWClass
         return "#{sCell=" + dest + "}";
     }
 
-    MWWorld::Ptr
-    Door::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Door::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Door> *ref =
-            ptr.get<ESM::Door>();
+        const MWWorld::LiveCellRef<ESM::Door> *ref = ptr.get<ESM::Door>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/door.hpp b/apps/openmw/mwclass/door.hpp
index 6cb297ca5..f789055ff 100644
--- a/apps/openmw/mwclass/door.hpp
+++ b/apps/openmw/mwclass/door.hpp
@@ -11,8 +11,7 @@ namespace MWClass
     {
             void ensureCustomData (const MWWorld::Ptr& ptr) const;
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/ingredient.cpp b/apps/openmw/mwclass/ingredient.cpp
index bdc67b452..bfe482e96 100644
--- a/apps/openmw/mwclass/ingredient.cpp
+++ b/apps/openmw/mwclass/ingredient.cpp
@@ -172,11 +172,9 @@ namespace MWClass
         return info;
     }
 
-    MWWorld::Ptr
-    Ingredient::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Ingredient::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Ingredient> *ref =
-            ptr.get<ESM::Ingredient>();
+        const MWWorld::LiveCellRef<ESM::Ingredient> *ref = ptr.get<ESM::Ingredient>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/ingredient.hpp b/apps/openmw/mwclass/ingredient.hpp
index 96fc7e8e4..dd156d314 100644
--- a/apps/openmw/mwclass/ingredient.hpp
+++ b/apps/openmw/mwclass/ingredient.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Ingredient : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/light.cpp b/apps/openmw/mwclass/light.cpp
index 626cde9ac..86f1b1d61 100644
--- a/apps/openmw/mwclass/light.cpp
+++ b/apps/openmw/mwclass/light.cpp
@@ -203,11 +203,9 @@ namespace MWClass
             return ptr.getCellRef().getChargeFloat();
     }
 
-    MWWorld::Ptr
-    Light::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Light::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Light> *ref =
-            ptr.get<ESM::Light>();
+        const MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/light.hpp b/apps/openmw/mwclass/light.hpp
index a52c3f568..7fbaa833a 100644
--- a/apps/openmw/mwclass/light.hpp
+++ b/apps/openmw/mwclass/light.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Light : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/lockpick.cpp b/apps/openmw/mwclass/lockpick.cpp
index b46159cbc..abf9f9c14 100644
--- a/apps/openmw/mwclass/lockpick.cpp
+++ b/apps/openmw/mwclass/lockpick.cpp
@@ -153,11 +153,9 @@ namespace MWClass
         return action;
     }
 
-    MWWorld::Ptr
-    Lockpick::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Lockpick::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Lockpick> *ref =
-            ptr.get<ESM::Lockpick>();
+        const MWWorld::LiveCellRef<ESM::Lockpick> *ref = ptr.get<ESM::Lockpick>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/lockpick.hpp b/apps/openmw/mwclass/lockpick.hpp
index b5b4844c3..7225cab11 100644
--- a/apps/openmw/mwclass/lockpick.hpp
+++ b/apps/openmw/mwclass/lockpick.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Lockpick : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/misc.cpp b/apps/openmw/mwclass/misc.cpp
index c8fdc2a8a..1c8e75f1f 100644
--- a/apps/openmw/mwclass/misc.cpp
+++ b/apps/openmw/mwclass/misc.cpp
@@ -182,8 +182,7 @@ namespace MWClass
         return info;
     }
 
-    MWWorld::Ptr
-    Miscellaneous::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Miscellaneous::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
         MWWorld::Ptr newPtr;
 
@@ -206,14 +205,14 @@ namespace MWClass
             // Really, I have no idea why moving ref out of conditional
             // scope causes list::push_back throwing std::bad_alloc
             MWWorld::ManualRef newRef(store, base);
-            MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
+            const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
                 newRef.getPtr().get<ESM::Miscellaneous>();
 
             newPtr = MWWorld::Ptr(cell.insert(ref), &cell);
             newPtr.getCellRef().setGoldValue(goldAmount);
             newPtr.getRefData().setCount(1);
         } else {
-            MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
+            const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
                 ptr.get<ESM::Miscellaneous>();
             newPtr = MWWorld::Ptr(cell.insert(ref), &cell);
         }
diff --git a/apps/openmw/mwclass/misc.hpp b/apps/openmw/mwclass/misc.hpp
index 679319e02..d9979fa87 100644
--- a/apps/openmw/mwclass/misc.hpp
+++ b/apps/openmw/mwclass/misc.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Miscellaneous : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/npc.cpp b/apps/openmw/mwclass/npc.cpp
index 8ef3c219a..42e28fc2f 100644
--- a/apps/openmw/mwclass/npc.cpp
+++ b/apps/openmw/mwclass/npc.cpp
@@ -1124,11 +1124,9 @@ namespace MWClass
         throw std::runtime_error(std::string("Unexpected soundgen type: ")+name);
     }
 
-    MWWorld::Ptr
-    Npc::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Npc::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::NPC> *ref =
-            ptr.get<ESM::NPC>();
+        const MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/npc.hpp b/apps/openmw/mwclass/npc.hpp
index acde83c5f..b62192367 100644
--- a/apps/openmw/mwclass/npc.hpp
+++ b/apps/openmw/mwclass/npc.hpp
@@ -14,8 +14,7 @@ namespace MWClass
     {
             void ensureCustomData (const MWWorld::Ptr& ptr) const;
 
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
             struct GMST
             {
diff --git a/apps/openmw/mwclass/potion.cpp b/apps/openmw/mwclass/potion.cpp
index e4928384d..f0875d138 100644
--- a/apps/openmw/mwclass/potion.cpp
+++ b/apps/openmw/mwclass/potion.cpp
@@ -166,11 +166,9 @@ namespace MWClass
         return action;
     }
 
-    MWWorld::Ptr
-    Potion::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Potion::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Potion> *ref =
-            ptr.get<ESM::Potion>();
+        const MWWorld::LiveCellRef<ESM::Potion> *ref = ptr.get<ESM::Potion>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/potion.hpp b/apps/openmw/mwclass/potion.hpp
index ac6e0d180..92f0ebcd9 100644
--- a/apps/openmw/mwclass/potion.hpp
+++ b/apps/openmw/mwclass/potion.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Potion : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/probe.cpp b/apps/openmw/mwclass/probe.cpp
index ac9ac56e8..010a73a3c 100644
--- a/apps/openmw/mwclass/probe.cpp
+++ b/apps/openmw/mwclass/probe.cpp
@@ -153,11 +153,9 @@ namespace MWClass
         return action;
     }
 
-    MWWorld::Ptr
-    Probe::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Probe::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Probe> *ref =
-            ptr.get<ESM::Probe>();
+        const MWWorld::LiveCellRef<ESM::Probe> *ref = ptr.get<ESM::Probe>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/probe.hpp b/apps/openmw/mwclass/probe.hpp
index d0a4b4947..2dc63b155 100644
--- a/apps/openmw/mwclass/probe.hpp
+++ b/apps/openmw/mwclass/probe.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Probe : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/repair.cpp b/apps/openmw/mwclass/repair.cpp
index 1940baa67..6d681a87c 100644
--- a/apps/openmw/mwclass/repair.cpp
+++ b/apps/openmw/mwclass/repair.cpp
@@ -147,11 +147,9 @@ namespace MWClass
         return info;
     }
 
-    MWWorld::Ptr
-    Repair::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Repair::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Repair> *ref =
-            ptr.get<ESM::Repair>();
+        const MWWorld::LiveCellRef<ESM::Repair> *ref = ptr.get<ESM::Repair>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/repair.hpp b/apps/openmw/mwclass/repair.hpp
index dce47167f..2dcf03ce2 100644
--- a/apps/openmw/mwclass/repair.hpp
+++ b/apps/openmw/mwclass/repair.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Repair : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/static.cpp b/apps/openmw/mwclass/static.cpp
index 5539f8375..a6863f400 100644
--- a/apps/openmw/mwclass/static.cpp
+++ b/apps/openmw/mwclass/static.cpp
@@ -52,11 +52,9 @@ namespace MWClass
         registerClass (typeid (ESM::Static).name(), instance);
     }
 
-    MWWorld::Ptr
-    Static::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    MWWorld::Ptr Static::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Static> *ref =
-            ptr.get<ESM::Static>();
+        const MWWorld::LiveCellRef<ESM::Static> *ref = ptr.get<ESM::Static>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/static.hpp b/apps/openmw/mwclass/static.hpp
index 9c4a61410..f2a5cef92 100644
--- a/apps/openmw/mwclass/static.hpp
+++ b/apps/openmw/mwclass/static.hpp
@@ -7,8 +7,7 @@ namespace MWClass
 {
     class Static : public MWWorld::Class
     {
-            virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            virtual MWWorld::Ptr copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwclass/weapon.cpp b/apps/openmw/mwclass/weapon.cpp
index db1448afc..1b40787c8 100644
--- a/apps/openmw/mwclass/weapon.cpp
+++ b/apps/openmw/mwclass/weapon.cpp
@@ -399,10 +399,9 @@ namespace MWClass
     }
 
     MWWorld::Ptr
-    Weapon::copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const
+    Weapon::copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         return MWWorld::Ptr(cell.insert(ref), &cell);
     }
diff --git a/apps/openmw/mwclass/weapon.hpp b/apps/openmw/mwclass/weapon.hpp
index 611e2edf0..aa87afc7a 100644
--- a/apps/openmw/mwclass/weapon.hpp
+++ b/apps/openmw/mwclass/weapon.hpp
@@ -8,7 +8,7 @@ namespace MWClass
     class Weapon : public MWWorld::Class
     {
             virtual MWWorld::Ptr
-            copyToCellImpl(const MWWorld::Ptr &ptr, MWWorld::CellStore &cell) const;
+            copyToCellImpl(const MWWorld::ConstPtr &ptr, MWWorld::CellStore &cell) const;
 
         public:
 
diff --git a/apps/openmw/mwworld/class.cpp b/apps/openmw/mwworld/class.cpp
index 8722187ab..7b57a2136 100644
--- a/apps/openmw/mwworld/class.cpp
+++ b/apps/openmw/mwworld/class.cpp
@@ -333,13 +333,13 @@ namespace MWWorld
     }
 
     MWWorld::Ptr
-    Class::copyToCellImpl(const Ptr &ptr, CellStore &cell) const
+    Class::copyToCellImpl(const ConstPtr &ptr, CellStore &cell) const
     {
-        throw std::runtime_error("unable to move class to cell");
+        throw std::runtime_error("unable to copy class to cell");
     }
 
     MWWorld::Ptr
-    Class::copyToCell(const Ptr &ptr, CellStore &cell) const
+    Class::copyToCell(const ConstPtr &ptr, CellStore &cell) const
     {
         Ptr newPtr = copyToCellImpl(ptr, cell);
         newPtr.getCellRef().unsetRefNum(); // This RefNum is only valid within the original cell of the reference
@@ -347,7 +347,7 @@ namespace MWWorld
     }
 
     MWWorld::Ptr
-    Class::copyToCell(const Ptr &ptr, CellStore &cell, const ESM::Position &pos) const
+    Class::copyToCell(const ConstPtr &ptr, CellStore &cell, const ESM::Position &pos) const
     {
         Ptr newPtr = copyToCell(ptr, cell);
         newPtr.getRefData().setPosition(pos);
diff --git a/apps/openmw/mwworld/class.hpp b/apps/openmw/mwworld/class.hpp
index 619508f74..26bd98aa4 100644
--- a/apps/openmw/mwworld/class.hpp
+++ b/apps/openmw/mwworld/class.hpp
@@ -66,7 +66,7 @@ namespace MWWorld
             boost::shared_ptr<Action> defaultItemActivate(const Ptr &ptr, const Ptr &actor) const;
             ///< Generate default action for activating inventory items
 
-            virtual Ptr copyToCellImpl(const Ptr &ptr, CellStore &cell) const;
+            virtual Ptr copyToCellImpl(const ConstPtr &ptr, CellStore &cell) const;
 
         public:
 
@@ -286,11 +286,9 @@ namespace MWWorld
             /// Get a blood texture suitable for \a ptr (see Blood Texture 0-2 in Morrowind.ini)
             virtual int getBloodTexture (const MWWorld::Ptr& ptr) const;
 
-            virtual Ptr
-            copyToCell(const Ptr &ptr, CellStore &cell) const;
+            virtual Ptr copyToCell(const ConstPtr &ptr, CellStore &cell) const;
 
-            virtual Ptr
-            copyToCell(const Ptr &ptr, CellStore &cell, const ESM::Position &pos) const;
+            virtual Ptr copyToCell(const ConstPtr &ptr, CellStore &cell, const ESM::Position &pos) const;
 
             virtual bool isActor() const {
                 return false;