diff --git a/apps/openmw/CMakeLists.txt b/apps/openmw/CMakeLists.txt
index 0c3a93e656..b32623b3f0 100644
--- a/apps/openmw/CMakeLists.txt
+++ b/apps/openmw/CMakeLists.txt
@@ -78,7 +78,7 @@ add_openmw_dir (mwworld
     actionequip timestamp actionalchemy cellstore actionapply actioneat
     store esmstore fallback actionrepair actionsoulgem livecellref actiondoor
     contentloader esmloader actiontrap cellreflist cellref weather projectilemanager
-    cellpreloader datetimemanager groundcoverstore magiceffects cell
+    cellpreloader datetimemanager groundcoverstore magiceffects cell ptrregistry
     )
 
 add_openmw_dir (mwphysics
diff --git a/apps/openmw/mwclass/misc.cpp b/apps/openmw/mwclass/misc.cpp
index fdb2a7274f..a7cfae503e 100644
--- a/apps/openmw/mwclass/misc.cpp
+++ b/apps/openmw/mwclass/misc.cpp
@@ -208,7 +208,7 @@ namespace MWClass
         }
         newPtr.getCellRef().unsetRefNum();
         newPtr.getRefData().setLuaScripts(nullptr);
-        MWBase::Environment::get().getWorldModel()->registerPtr(newPtr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(newPtr);
         return newPtr;
     }
 
@@ -229,7 +229,7 @@ namespace MWClass
             newPtr = MWWorld::Ptr(cell.insert(ref), &cell);
         }
         ptr.getRefData().setLuaScripts(nullptr);
-        MWBase::Environment::get().getWorldModel()->registerPtr(newPtr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(newPtr);
         return newPtr;
     }
 
diff --git a/apps/openmw/mwlua/cellbindings.cpp b/apps/openmw/mwlua/cellbindings.cpp
index 35f9af0f2b..83102df61f 100644
--- a/apps/openmw/mwlua/cellbindings.cpp
+++ b/apps/openmw/mwlua/cellbindings.cpp
@@ -83,7 +83,7 @@ namespace MWLua
                 auto visitor = [&](const MWWorld::Ptr& ptr) {
                     if (ptr.getRefData().isDeleted())
                         return true;
-                    MWBase::Environment::get().getWorldModel()->registerPtr(ptr);
+                    MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(ptr);
                     if (getLiveCellRefType(ptr.mRef) == ptr.getType())
                         res->push_back(getId(ptr));
                     return true;
diff --git a/apps/openmw/mwlua/engineevents.cpp b/apps/openmw/mwlua/engineevents.cpp
index 0c5abe6cef..7c1342aefe 100644
--- a/apps/openmw/mwlua/engineevents.cpp
+++ b/apps/openmw/mwlua/engineevents.cpp
@@ -74,7 +74,7 @@ namespace MWLua
     private:
         MWWorld::Ptr getPtr(const ESM::RefNum& id) const
         {
-            MWWorld::Ptr res = mWorldModel->getPtr(id);
+            MWWorld::Ptr res = mWorldModel->getPtrRegistry().getOrDefault(id);
             if (res.isEmpty() && Settings::lua().mLuaDebug)
                 Log(Debug::Verbose) << "Can not find object" << id.toString() << " when calling engine hanglers";
             return res;
diff --git a/apps/openmw/mwlua/luaevents.cpp b/apps/openmw/mwlua/luaevents.cpp
index b036fea3b6..d96ae63579 100644
--- a/apps/openmw/mwlua/luaevents.cpp
+++ b/apps/openmw/mwlua/luaevents.cpp
@@ -40,7 +40,7 @@ namespace MWLua
         mGlobalEventBatch.clear();
         for (const Local& e : mLocalEventBatch)
         {
-            MWWorld::Ptr ptr = MWBase::Environment::get().getWorldModel()->getPtr(e.mDest);
+            MWWorld::Ptr ptr = MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(e.mDest);
             LocalScripts* scripts = ptr.isEmpty() ? nullptr : ptr.getRefData().getLuaScripts();
             if (scripts)
                 scripts->receiveEvent(e.mEventName, e.mEventData);
diff --git a/apps/openmw/mwlua/luamanagerimp.cpp b/apps/openmw/mwlua/luamanagerimp.cpp
index 0447a24260..50d4d9c11d 100644
--- a/apps/openmw/mwlua/luamanagerimp.cpp
+++ b/apps/openmw/mwlua/luamanagerimp.cpp
@@ -136,7 +136,7 @@ namespace MWLua
         if (!mPlayer.isInCell() || !newPlayerPtr.isInCell() || mPlayer.getCell() != newPlayerPtr.getCell())
         {
             mPlayer = newPlayerPtr; // player was moved to another cell, update ptr in registry
-            MWBase::Environment::get().getWorldModel()->registerPtr(mPlayer);
+            MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(mPlayer);
         }
 
         mWorldView.update();
@@ -299,7 +299,7 @@ namespace MWLua
         if (localScripts)
         {
             mActiveLocalScripts.erase(localScripts);
-            if (!MWBase::Environment::get().getWorldModel()->getPtr(getId(ptr)).isEmpty())
+            if (!MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(getId(ptr)).isEmpty())
                 mEngineEvents.addToQueue(EngineEvents::OnInactive{ getId(ptr) });
         }
     }
@@ -401,7 +401,7 @@ namespace MWLua
             return;
         }
 
-        MWBase::Environment::get().getWorldModel()->registerPtr(ptr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(ptr);
         LocalScripts* scripts = createLocalScripts(ptr);
 
         scripts->setSerializer(mLocalSerializer.get());
@@ -409,7 +409,7 @@ namespace MWLua
         scripts->load(data);
 
         // LiveCellRef is usually copied after loading, so this Ptr will become invalid and should be deregistered.
-        MWBase::Environment::get().getWorldModel()->deregisterPtr(ptr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().remove(ptr);
     }
 
     void LuaManager::reloadAllScripts()
@@ -430,7 +430,7 @@ namespace MWLua
             mGlobalScripts.load(data);
         }
 
-        for (const auto& [id, ptr] : MWBase::Environment::get().getWorldModel()->getAllPtrs())
+        for (const auto& [id, ptr] : MWBase::Environment::get().getWorldModel()->getPtrRegistry())
         { // Reload local scripts
             LocalScripts* scripts = ptr.getRefData().getLuaScripts();
             if (scripts == nullptr)
diff --git a/apps/openmw/mwlua/objectbindings.cpp b/apps/openmw/mwlua/objectbindings.cpp
index 5e5c380469..5ad80c97eb 100644
--- a/apps/openmw/mwlua/objectbindings.cpp
+++ b/apps/openmw/mwlua/objectbindings.cpp
@@ -497,7 +497,7 @@ namespace MWLua
                 while (it.getType() != -1)
                 {
                     const MWWorld::Ptr& item = *(it++);
-                    MWBase::Environment::get().getWorldModel()->registerPtr(item);
+                    MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(item);
                     list->push_back(getId(item));
                 }
                 return ObjectList<ObjectT>{ list };
@@ -516,7 +516,7 @@ namespace MWLua
                 {
                     if (item.getCellRef().getRefId() == itemId)
                     {
-                        MWBase::Environment::get().getWorldModel()->registerPtr(item);
+                        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(item);
                         return ObjectT(getId(item));
                     }
                 }
@@ -531,7 +531,7 @@ namespace MWLua
                 {
                     if (item.getCellRef().getRefId() == itemId)
                     {
-                        MWBase::Environment::get().getWorldModel()->registerPtr(item);
+                        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(item);
                         list->push_back(getId(item));
                     }
                 }
diff --git a/apps/openmw/mwlua/types/actor.cpp b/apps/openmw/mwlua/types/actor.cpp
index bf0866bc0f..d1f0e1ec8c 100644
--- a/apps/openmw/mwlua/types/actor.cpp
+++ b/apps/openmw/mwlua/types/actor.cpp
@@ -32,7 +32,8 @@ namespace MWLua
             MWWorld::Ptr itemPtr;
             if (std::holds_alternative<ObjectId>(item))
             {
-                itemPtr = MWBase::Environment::get().getWorldModel()->getPtr(std::get<ObjectId>(item));
+                itemPtr = MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(
+                    std::get<ObjectId>(item));
                 if (old_it != store.end() && *old_it == itemPtr)
                     return true; // already equipped
                 if (itemPtr.isEmpty() || itemPtr.getRefData().getCount() == 0
@@ -217,7 +218,7 @@ namespace MWLua
                 auto it = store.getSlot(slot);
                 if (it == store.end())
                     continue;
-                MWBase::Environment::get().getWorldModel()->registerPtr(*it);
+                MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(*it);
                 if (dynamic_cast<const GObject*>(&o))
                     equipment[slot] = sol::make_object(lua, GObject(*it));
                 else
@@ -233,7 +234,7 @@ namespace MWLua
             auto it = store.getSlot(slot);
             if (it == store.end())
                 return sol::nil;
-            MWBase::Environment::get().getWorldModel()->registerPtr(*it);
+            MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(*it);
             if (dynamic_cast<const GObject*>(&o))
                 return sol::make_object(lua, GObject(*it));
             else
diff --git a/apps/openmw/mwlua/worldview.cpp b/apps/openmw/mwlua/worldview.cpp
index f5699dff89..80f836c73b 100644
--- a/apps/openmw/mwlua/worldview.cpp
+++ b/apps/openmw/mwlua/worldview.cpp
@@ -58,7 +58,7 @@ namespace MWLua
 
     void WorldView::objectAddedToScene(const MWWorld::Ptr& ptr)
     {
-        MWBase::Environment::get().getWorldModel()->registerPtr(ptr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(ptr);
         ObjectGroup* group = chooseGroup(ptr);
         if (group)
             addToGroup(*group, ptr);
@@ -81,13 +81,13 @@ namespace MWLua
     void WorldView::load(ESM::ESMReader& esm)
     {
         esm.getHNT(mSimulationTime, "LUAW");
-        MWBase::Environment::get().getWorldModel()->setLastGeneratedRefNum(esm.getFormId(true));
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().setLastGenerated(esm.getFormId(true));
     }
 
     void WorldView::save(ESM::ESMWriter& esm) const
     {
         esm.writeHNT("LUAW", mSimulationTime);
-        esm.writeFormId(MWBase::Environment::get().getWorldModel()->getLastGeneratedRefNum(), true);
+        esm.writeFormId(MWBase::Environment::get().getWorldModel()->getPtrRegistry().getLastGenerated(), true);
     }
 
     void WorldView::ObjectGroup::updateList()
diff --git a/apps/openmw/mwscript/globalscripts.cpp b/apps/openmw/mwscript/globalscripts.cpp
index 60bf58953a..d95f9c40ae 100644
--- a/apps/openmw/mwscript/globalscripts.cpp
+++ b/apps/openmw/mwscript/globalscripts.cpp
@@ -63,7 +63,7 @@ namespace
             if (pair.second.empty())
                 return MWWorld::Ptr();
             else if (pair.first.hasContentFile())
-                return MWBase::Environment::get().getWorldModel()->getPtr(pair.first);
+                return MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(pair.first);
             return MWBase::Environment::get().getWorld()->searchPtr(pair.second, false);
         }
     };
diff --git a/apps/openmw/mwworld/cellstore.cpp b/apps/openmw/mwworld/cellstore.cpp
index 4036c378db..67242d9003 100644
--- a/apps/openmw/mwworld/cellstore.cpp
+++ b/apps/openmw/mwworld/cellstore.cpp
@@ -275,7 +275,7 @@ namespace
                         iter->mData.enable();
                         MWBase::Environment::get().getWorld()->disable(ptr);
                     }
-                    MWBase::Environment::get().getWorldModel()->registerPtr(ptr);
+                    MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(ptr);
                     return;
                 }
 
@@ -290,7 +290,7 @@ namespace
         collection.mList.push_back(ref);
 
         MWWorld::LiveCellRefBase* base = &collection.mList.back();
-        MWBase::Environment::get().getWorldModel()->registerPtr(MWWorld::Ptr(base, cellstore));
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(MWWorld::Ptr(base, cellstore));
     }
 
     // this function allows us to link a CellRefList<T> to the associated recNameInt, and apply a function
@@ -443,7 +443,8 @@ namespace MWWorld
             throw std::runtime_error(
                 "moveTo: can't move object from a non-loaded cell (how did you get this object anyway?)");
 
-        MWBase::Environment::get().getWorldModel()->registerPtr(MWWorld::Ptr(object.getBase(), cellToMoveTo));
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(
+            MWWorld::Ptr(object.getBase(), cellToMoveTo));
 
         MovedRefTracker::iterator found = mMovedHere.find(object.getBase());
         if (found != mMovedHere.end())
@@ -1041,7 +1042,7 @@ namespace MWWorld
             }
 
             // Search for the reference. It might no longer exist if its content file was removed.
-            Ptr movedRef = MWBase::Environment::get().getWorldModel()->getPtr(refnum);
+            Ptr movedRef = MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(refnum);
             if (movedRef.isEmpty())
             {
                 Log(Debug::Warning) << "Warning: Dropping moved ref tag for " << refnum.mIndex
diff --git a/apps/openmw/mwworld/class.cpp b/apps/openmw/mwworld/class.cpp
index 28777656c8..ee6f3cc1ab 100644
--- a/apps/openmw/mwworld/class.cpp
+++ b/apps/openmw/mwworld/class.cpp
@@ -375,7 +375,7 @@ namespace MWWorld
         newPtr.getCellRef().unsetRefNum(); // This RefNum is only valid within the original cell of the reference
         newPtr.getRefData().setCount(count);
         newPtr.getRefData().setLuaScripts(nullptr);
-        MWBase::Environment::get().getWorldModel()->registerPtr(newPtr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(newPtr);
         if (hasInventoryStore(newPtr))
             getInventoryStore(newPtr).setActor(newPtr);
         return newPtr;
@@ -385,7 +385,7 @@ namespace MWWorld
     {
         Ptr newPtr = copyToCellImpl(ptr, cell);
         ptr.getRefData().setLuaScripts(nullptr);
-        MWBase::Environment::get().getWorldModel()->registerPtr(newPtr);
+        MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(newPtr);
         if (hasInventoryStore(newPtr))
             getInventoryStore(newPtr).setActor(newPtr);
         return newPtr;
diff --git a/apps/openmw/mwworld/containerstore.cpp b/apps/openmw/mwworld/containerstore.cpp
index 5de939b6e9..62285c29a6 100644
--- a/apps/openmw/mwworld/containerstore.cpp
+++ b/apps/openmw/mwworld/containerstore.cpp
@@ -308,7 +308,7 @@ MWWorld::ContainerStoreIterator MWWorld::ContainerStore::add(
 
     // The copy of the original item we just made
     MWWorld::Ptr item = *it;
-    MWBase::Environment::get().getWorldModel()->registerPtr(item);
+    MWBase::Environment::get().getWorldModel()->getPtrRegistry().insert(item);
 
     // we may have copied an item from the world, so reset a few things first
     item.getRefData().setBaseNode(
diff --git a/apps/openmw/mwworld/ptr.cpp b/apps/openmw/mwworld/ptr.cpp
index a0826474c5..5570856132 100644
--- a/apps/openmw/mwworld/ptr.cpp
+++ b/apps/openmw/mwworld/ptr.cpp
@@ -24,7 +24,7 @@ namespace MWWorld
     SafePtr::SafePtr(const Ptr& ptr)
         : mId(ptr.getCellRef().getRefNum())
         , mPtr(ptr)
-        , mLastUpdate(MWBase::Environment::get().getWorldModel()->getPtrIndexUpdateCounter())
+        , mLastUpdate(MWBase::Environment::get().getWorldModel()->getPtrRegistry().getRevision())
     {
     }
 
@@ -39,11 +39,11 @@ namespace MWWorld
 
     void SafePtr::update() const
     {
-        WorldModel& w = *MWBase::Environment::get().getWorldModel();
-        if (mLastUpdate < w.getPtrIndexUpdateCounter())
+        const PtrRegistry& registry = MWBase::Environment::get().getWorldModel()->getPtrRegistry();
+        if (mLastUpdate < registry.getRevision())
         {
-            mPtr = w.getPtr(mId);
-            mLastUpdate = w.getPtrIndexUpdateCounter();
+            mPtr = registry.getOrDefault(mId);
+            mLastUpdate = registry.getRevision();
         }
     }
 }
diff --git a/apps/openmw/mwworld/ptrregistry.hpp b/apps/openmw/mwworld/ptrregistry.hpp
new file mode 100644
index 0000000000..4ecde7b52f
--- /dev/null
+++ b/apps/openmw/mwworld/ptrregistry.hpp
@@ -0,0 +1,59 @@
+#ifndef OPENMW_APPS_OPENMW_MWWORLD_PTRREGISTRY_H
+#define OPENMW_APPS_OPENMW_MWWORLD_PTRREGISTRY_H
+
+#include "ptr.hpp"
+
+#include "components/esm3/cellref.hpp"
+
+#include <unordered_map>
+
+namespace MWWorld
+{
+    class PtrRegistry
+    {
+    public:
+        std::size_t getRevision() const { return mRevision; }
+
+        ESM::RefNum getLastGenerated() const { return mLastGenerated; }
+
+        auto begin() const { return mIndex.cbegin(); }
+
+        auto end() const { return mIndex.cend(); }
+
+        Ptr getOrDefault(ESM::RefNum refNum) const
+        {
+            const auto it = mIndex.find(refNum);
+            if (it != mIndex.end())
+                return it->second;
+            return Ptr();
+        }
+
+        void setLastGenerated(ESM::RefNum v) { mLastGenerated = v; }
+
+        void clear()
+        {
+            mIndex.clear();
+            mLastGenerated = ESM::RefNum{};
+            mRevision = 0;
+        }
+
+        void insert(const Ptr& ptr)
+        {
+            mIndex[ptr.getCellRef().getOrAssignRefNum(mLastGenerated)] = ptr;
+            ++mRevision;
+        }
+
+        void remove(const Ptr& ptr)
+        {
+            mIndex.erase(ptr.getCellRef().getRefNum());
+            ++mRevision;
+        }
+
+    private:
+        std::size_t mRevision = 0;
+        std::unordered_map<ESM::RefNum, Ptr> mIndex;
+        ESM::RefNum mLastGenerated;
+    };
+}
+
+#endif
diff --git a/apps/openmw/mwworld/worldimp.cpp b/apps/openmw/mwworld/worldimp.cpp
index 349215460c..78a33bcdbf 100644
--- a/apps/openmw/mwworld/worldimp.cpp
+++ b/apps/openmw/mwworld/worldimp.cpp
@@ -1851,7 +1851,8 @@ namespace MWWorld
 
         facedObject = rayToObject.mHitObject;
         if (facedObject.isEmpty() && rayToObject.mHitRefnum.isSet())
-            facedObject = MWBase::Environment::get().getWorldModel()->getPtr(rayToObject.mHitRefnum);
+            facedObject
+                = MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(rayToObject.mHitRefnum);
         if (rayToObject.mHit)
             mDistanceToFacedObject = (rayToObject.mRatio * maxDistance) - camDist;
         else
@@ -1868,7 +1869,8 @@ namespace MWWorld
         res.mHitNormal = rayRes.mHitNormalWorld;
         res.mHitObject = rayRes.mHitObject;
         if (res.mHitObject.isEmpty() && rayRes.mHitRefnum.isSet())
-            res.mHitObject = MWBase::Environment::get().getWorldModel()->getPtr(rayRes.mHitRefnum);
+            res.mHitObject
+                = MWBase::Environment::get().getWorldModel()->getPtrRegistry().getOrDefault(rayRes.mHitRefnum);
         return res.mHit;
     }
 
diff --git a/apps/openmw/mwworld/worldmodel.cpp b/apps/openmw/mwworld/worldmodel.cpp
index ca69a7ff39..3841cc6fdf 100644
--- a/apps/openmw/mwworld/worldmodel.cpp
+++ b/apps/openmw/mwworld/worldmodel.cpp
@@ -82,9 +82,7 @@ MWWorld::CellStore& MWWorld::WorldModel::insertCellStore(const ESM::Cell& cell)
 
 void MWWorld::WorldModel::clear()
 {
-    mPtrIndex.clear();
-    mPtrIndexUpdateCounter = 0;
-    mLastGeneratedRefnum = ESM::RefNum{};
+    mPtrRegistry.clear();
     mInteriors.clear();
     mExteriors.clear();
     mCells.clear();
@@ -92,27 +90,6 @@ void MWWorld::WorldModel::clear()
     mIdCacheIndex = 0;
 }
 
-void MWWorld::WorldModel::registerPtr(const MWWorld::Ptr& ptr)
-{
-    mPtrIndex[ptr.getCellRef().getOrAssignRefNum(mLastGeneratedRefnum)] = ptr;
-    mPtrIndexUpdateCounter++;
-}
-
-void MWWorld::WorldModel::deregisterPtr(const MWWorld::Ptr& ptr)
-{
-    mPtrIndex.erase(ptr.getCellRef().getRefNum());
-    mPtrIndexUpdateCounter++;
-}
-
-MWWorld::Ptr MWWorld::WorldModel::getPtr(const ESM::RefNum& refNum) const
-{
-    auto it = mPtrIndex.find(refNum);
-    if (it != mPtrIndex.end())
-        return it->second;
-    else
-        return MWWorld::Ptr();
-}
-
 MWWorld::Ptr MWWorld::WorldModel::getPtrAndCache(const ESM::RefId& name, CellStore& cellStore)
 {
     Ptr ptr = cellStore.getPtr(name);
diff --git a/apps/openmw/mwworld/worldmodel.hpp b/apps/openmw/mwworld/worldmodel.hpp
index a83e29dd83..53a46c78d1 100644
--- a/apps/openmw/mwworld/worldmodel.hpp
+++ b/apps/openmw/mwworld/worldmodel.hpp
@@ -12,6 +12,7 @@
 
 #include "cellstore.hpp"
 #include "ptr.hpp"
+#include "ptrregistry.hpp"
 
 namespace ESM
 {
@@ -51,17 +52,10 @@ namespace MWWorld
         CellStore& getCell(std::string_view name, bool forceLoad = true); // interior or named exterior
         CellStore& getCell(const ESM::RefId& Id, bool forceLoad = true);
 
-        void registerPtr(const MWWorld::Ptr& ptr);
-        void deregisterPtr(const MWWorld::Ptr& ptr);
-        ESM::RefNum getLastGeneratedRefNum() const { return mLastGeneratedRefnum; }
-        void setLastGeneratedRefNum(ESM::RefNum v) { mLastGeneratedRefnum = v; }
-        size_t getPtrIndexUpdateCounter() const { return mPtrIndexUpdateCounter; }
-        const std::unordered_map<ESM::RefNum, Ptr>& getAllPtrs() const { return mPtrIndex; }
-
-        Ptr getPtr(const ESM::RefNum& refNum) const;
-
         Ptr getPtr(const ESM::RefId& name);
 
+        PtrRegistry& getPtrRegistry() { return mPtrRegistry; }
+
         template <typename Fn>
         void forEachLoadedCellStore(Fn&& fn)
         {
@@ -90,9 +84,7 @@ namespace MWWorld
         mutable std::map<ESM::ExteriorCellLocation, CellStore*> mExteriors;
         std::vector<std::pair<ESM::RefId, CellStore*>> mIdCache;
         std::size_t mIdCacheIndex = 0;
-        std::unordered_map<ESM::RefNum, Ptr> mPtrIndex;
-        std::size_t mPtrIndexUpdateCounter = 0;
-        ESM::RefNum mLastGeneratedRefnum;
+        PtrRegistry mPtrRegistry;
 
         CellStore& getOrInsertCellStore(const ESM::Cell& cell);