diff --git a/apps/navmeshtool/worldspacedata.cpp b/apps/navmeshtool/worldspacedata.cpp
index 8d2ac7382b..7f579f8fde 100644
--- a/apps/navmeshtool/worldspacedata.cpp
+++ b/apps/navmeshtool/worldspacedata.cpp
@@ -103,8 +103,7 @@ namespace NavMeshTool
 
             Log(Debug::Debug) << "Loaded " << cellRefs.size() << " cell refs";
 
-            const auto getKey
-                = [](const EsmLoader::Record<CellRef>& v) -> const ESM::RefNum& { return v.mValue.mRefNum; };
+            const auto getKey = [](const EsmLoader::Record<CellRef>& v) -> ESM::RefNum { return v.mValue.mRefNum; };
             std::vector<CellRef> result = prepareRecords(cellRefs, getKey);
 
             Log(Debug::Debug) << "Prepared " << result.size() << " unique cell refs";
diff --git a/apps/openmw/mwlua/engineevents.cpp b/apps/openmw/mwlua/engineevents.cpp
index c838ccfcba..0fbb13f1cf 100644
--- a/apps/openmw/mwlua/engineevents.cpp
+++ b/apps/openmw/mwlua/engineevents.cpp
@@ -87,7 +87,7 @@ namespace MWLua
         void operator()(const OnNewExterior& event) const { mGlobalScripts.onNewExterior(GCell{ &event.mCell }); }
 
     private:
-        MWWorld::Ptr getPtr(const ESM::RefNum& id) const
+        MWWorld::Ptr getPtr(ESM::RefNum id) const
         {
             MWWorld::Ptr res = mWorldModel->getPtr(id);
             if (res.isEmpty() && Settings::lua().mLuaDebug)
@@ -103,7 +103,7 @@ namespace MWLua
                 return ptr.getRefData().getLuaScripts();
         }
 
-        LocalScripts* getLocalScripts(const ESM::RefNum& id) const { return getLocalScripts(getPtr(id)); }
+        LocalScripts* getLocalScripts(ESM::RefNum id) const { return getLocalScripts(getPtr(id)); }
 
         GlobalScripts& mGlobalScripts;
         MWWorld::WorldModel* mWorldModel = MWBase::Environment::get().getWorldModel();
diff --git a/apps/openmw/mwlua/luaevents.cpp b/apps/openmw/mwlua/luaevents.cpp
index b036fea3b6..02ea3415d2 100644
--- a/apps/openmw/mwlua/luaevents.cpp
+++ b/apps/openmw/mwlua/luaevents.cpp
@@ -52,7 +52,7 @@ namespace MWLua
     }
 
     template <typename Event>
-    static void saveEvent(ESM::ESMWriter& esm, const ESM::RefNum& dest, const Event& event)
+    static void saveEvent(ESM::ESMWriter& esm, ESM::RefNum dest, const Event& event)
     {
         esm.writeHNString("LUAE", event.mEventName);
         esm.writeFormId(dest, true);
diff --git a/apps/openmw/mwlua/object.hpp b/apps/openmw/mwlua/object.hpp
index fcf225de85..b42b092302 100644
--- a/apps/openmw/mwlua/object.hpp
+++ b/apps/openmw/mwlua/object.hpp
@@ -16,7 +16,7 @@ namespace MWLua
     // ObjectId is a unique identifier of a game object.
     // It can change only if the order of content files was change.
     using ObjectId = ESM::RefNum;
-    inline const ObjectId& getId(const MWWorld::Ptr& ptr)
+    inline ObjectId getId(const MWWorld::Ptr& ptr)
     {
         return ptr.getCellRef().getRefNum();
     }
diff --git a/apps/openmw/mwlua/objectlists.cpp b/apps/openmw/mwlua/objectlists.cpp
index 40b1ab93fa..e7b3bb2e06 100644
--- a/apps/openmw/mwlua/objectlists.cpp
+++ b/apps/openmw/mwlua/objectlists.cpp
@@ -75,7 +75,7 @@ namespace MWLua
         if (mChanged)
         {
             mList->clear();
-            for (const ObjectId& id : mSet)
+            for (ObjectId id : mSet)
                 mList->push_back(id);
             mChanged = false;
         }
diff --git a/apps/openmw/mwlua/userdataserializer.cpp b/apps/openmw/mwlua/userdataserializer.cpp
index 6565ee0bde..478f725d7c 100644
--- a/apps/openmw/mwlua/userdataserializer.cpp
+++ b/apps/openmw/mwlua/userdataserializer.cpp
@@ -52,7 +52,7 @@ namespace MWLua
             {
                 std::vector<ESM::RefNum> buf;
                 buf.reserve(objList->size());
-                for (const ESM::RefNum& v : *objList)
+                for (ESM::RefNum v : *objList)
                     buf.push_back({ Misc::toLittleEndian(v.mIndex), Misc::toLittleEndian(v.mContentFile) });
                 append(out, sObjListTypeName, buf.data(), buf.size() * sizeof(ESM::RefNum));
             }
diff --git a/apps/openmw/mwrender/objectpaging.cpp b/apps/openmw/mwrender/objectpaging.cpp
index 3579badee2..385ce46fff 100644
--- a/apps/openmw/mwrender/objectpaging.cpp
+++ b/apps/openmw/mwrender/objectpaging.cpp
@@ -437,7 +437,7 @@ namespace MWRender
     class AddRefnumMarkerVisitor : public osg::NodeVisitor
     {
     public:
-        AddRefnumMarkerVisitor(const ESM::RefNum& refnum)
+        AddRefnumMarkerVisitor(ESM::RefNum refnum)
             : osg::NodeVisitor(TRAVERSE_ALL_CHILDREN)
             , mRefnum(refnum)
         {
@@ -896,7 +896,7 @@ namespace MWRender
     };
 
     bool ObjectPaging::enableObject(
-        int type, const ESM::RefNum& refnum, const osg::Vec3f& pos, const osg::Vec2i& cell, bool enabled)
+        int type, ESM::RefNum refnum, const osg::Vec3f& pos, const osg::Vec2i& cell, bool enabled)
     {
         if (!typeFilter(type, false))
             return false;
@@ -923,8 +923,7 @@ namespace MWRender
         return true;
     }
 
-    bool ObjectPaging::blacklistObject(
-        int type, const ESM::RefNum& refnum, const osg::Vec3f& pos, const osg::Vec2i& cell)
+    bool ObjectPaging::blacklistObject(int type, ESM::RefNum refnum, const osg::Vec3f& pos, const osg::Vec2i& cell)
     {
         if (!typeFilter(type, false))
             return false;
diff --git a/apps/openmw/mwrender/objectpaging.hpp b/apps/openmw/mwrender/objectpaging.hpp
index d677c172f2..6085887b9c 100644
--- a/apps/openmw/mwrender/objectpaging.hpp
+++ b/apps/openmw/mwrender/objectpaging.hpp
@@ -41,11 +41,10 @@ namespace MWRender
         unsigned int getNodeMask() override;
 
         /// @return true if view needs rebuild
-        bool enableObject(
-            int type, const ESM::RefNum& refnum, const osg::Vec3f& pos, const osg::Vec2i& cell, bool enabled);
+        bool enableObject(int type, ESM::RefNum refnum, const osg::Vec3f& pos, const osg::Vec2i& cell, bool enabled);
 
         /// @return true if view needs rebuild
-        bool blacklistObject(int type, const ESM::RefNum& refnum, const osg::Vec3f& pos, const osg::Vec2i& cell);
+        bool blacklistObject(int type, ESM::RefNum refnum, const osg::Vec3f& pos, const osg::Vec2i& cell);
 
         void clear();
 
diff --git a/apps/openmw/mwrender/renderingmanager.cpp b/apps/openmw/mwrender/renderingmanager.cpp
index c9750ec0b9..6155325410 100644
--- a/apps/openmw/mwrender/renderingmanager.cpp
+++ b/apps/openmw/mwrender/renderingmanager.cpp
@@ -1644,7 +1644,7 @@ namespace MWRender
     {
         if (!ptr.isInCell() || !ptr.getCell()->isExterior() || !mObjectPaging)
             return;
-        const ESM::RefNum& refnum = ptr.getCellRef().getRefNum();
+        ESM::RefNum refnum = ptr.getCellRef().getRefNum();
         if (!refnum.hasContentFile())
             return;
         if (mObjectPaging->blacklistObject(type, refnum, ptr.getCellRef().getPosition().asVec3(),
diff --git a/apps/openmw/mwworld/cellref.cpp b/apps/openmw/mwworld/cellref.cpp
index 35a04574ee..d9a017fe68 100644
--- a/apps/openmw/mwworld/cellref.cpp
+++ b/apps/openmw/mwworld/cellref.cpp
@@ -30,17 +30,17 @@ namespace MWWorld
     {
     }
 
-    const ESM::RefNum& CellRef::getRefNum() const noexcept
+    ESM::RefNum CellRef::getRefNum() const noexcept
     {
         return std::visit(ESM::VisitOverload{
-                              [&](const ESM4::Reference& ref) -> const ESM::RefNum& { return ref.mId; },
-                              [&](const ESM4::ActorCharacter& ref) -> const ESM::RefNum& { return ref.mId; },
-                              [&](const ESM::CellRef& ref) -> const ESM::RefNum& { return ref.mRefNum; },
+                              [&](const ESM4::Reference& ref) -> ESM::RefNum { return ref.mId; },
+                              [&](const ESM4::ActorCharacter& ref) -> ESM::RefNum { return ref.mId; },
+                              [&](const ESM::CellRef& ref) -> ESM::RefNum { return ref.mRefNum; },
                           },
             mCellRef.mVariant);
     }
 
-    const ESM::RefNum& CellRef::getOrAssignRefNum(ESM::RefNum& lastAssignedRefNum)
+    ESM::RefNum CellRef::getOrAssignRefNum(ESM::RefNum& lastAssignedRefNum)
     {
         ESM::RefNum& refNum = std::visit(ESM::VisitOverload{
                                              [&](ESM4::Reference& ref) -> ESM::RefNum& { return ref.mId; },
diff --git a/apps/openmw/mwworld/cellref.hpp b/apps/openmw/mwworld/cellref.hpp
index 1943fd9b54..954babe481 100644
--- a/apps/openmw/mwworld/cellref.hpp
+++ b/apps/openmw/mwworld/cellref.hpp
@@ -27,11 +27,11 @@ namespace MWWorld
         explicit CellRef(const ESM4::ActorCharacter& ref);
 
         // Note: Currently unused for items in containers
-        const ESM::RefNum& getRefNum() const noexcept;
+        ESM::RefNum getRefNum() const noexcept;
 
         // Returns RefNum.
         // If RefNum is not set, assigns a generated one and changes the "lastAssignedRefNum" counter.
-        const ESM::RefNum& getOrAssignRefNum(ESM::RefNum& lastAssignedRefNum);
+        ESM::RefNum getOrAssignRefNum(ESM::RefNum& lastAssignedRefNum);
 
         void setRefNum(ESM::RefNum refNum);
 
diff --git a/apps/openmw/mwworld/cellreflist.hpp b/apps/openmw/mwworld/cellreflist.hpp
index 12f086e15d..187fff4287 100644
--- a/apps/openmw/mwworld/cellreflist.hpp
+++ b/apps/openmw/mwworld/cellreflist.hpp
@@ -38,7 +38,7 @@ namespace MWWorld
         }
 
         /// Remove all references with the given refNum from this list.
-        void remove(const ESM::RefNum& refNum)
+        void remove(ESM::RefNum refNum)
         {
             for (typename List::iterator it = mList.begin(); it != mList.end();)
             {
diff --git a/apps/openmw/mwworld/cellstore.cpp b/apps/openmw/mwworld/cellstore.cpp
index 61de2ab90d..f7ec3ddcba 100644
--- a/apps/openmw/mwworld/cellstore.cpp
+++ b/apps/openmw/mwworld/cellstore.cpp
@@ -660,10 +660,10 @@ namespace MWWorld
 
     class RefNumSearchVisitor
     {
-        const ESM::RefNum& mRefNum;
+        ESM::RefNum mRefNum;
 
     public:
-        RefNumSearchVisitor(const ESM::RefNum& refNum)
+        RefNumSearchVisitor(ESM::RefNum refNum)
             : mRefNum(refNum)
         {
         }
diff --git a/apps/openmw/mwworld/ptrregistry.hpp b/apps/openmw/mwworld/ptrregistry.hpp
index b640a22bfe..c5ce371538 100644
--- a/apps/openmw/mwworld/ptrregistry.hpp
+++ b/apps/openmw/mwworld/ptrregistry.hpp
@@ -45,7 +45,7 @@ namespace MWWorld
 
         void remove(const LiveCellRefBase& ref) noexcept
         {
-            const ESM::RefNum& refNum = ref.mRef.getRefNum();
+            ESM::RefNum refNum = ref.mRef.getRefNum();
             if (!refNum.isSet())
                 return;
             auto it = mIndex.find(refNum);
diff --git a/apps/openmw/mwworld/scene.cpp b/apps/openmw/mwworld/scene.cpp
index b5aff875bd..3d96de6749 100644
--- a/apps/openmw/mwworld/scene.cpp
+++ b/apps/openmw/mwworld/scene.cpp
@@ -111,7 +111,7 @@ namespace
         std::string model = getModel(ptr);
         const auto rotation = makeDirectNodeRotation(ptr);
 
-        const ESM::RefNum& refnum = ptr.getCellRef().getRefNum();
+        ESM::RefNum refnum = ptr.getCellRef().getRefNum();
         if (!refnum.hasContentFile() || !std::binary_search(pagedRefs.begin(), pagedRefs.end(), refnum))
             ptr.getClass().insertObjectRendering(ptr, model, rendering);
         else
@@ -259,7 +259,7 @@ namespace
         return false;
     }
 
-    bool removeFromSorted(const ESM::RefNum& refNum, std::vector<ESM::RefNum>& pagedRefs)
+    bool removeFromSorted(ESM::RefNum refNum, std::vector<ESM::RefNum>& pagedRefs)
     {
         const auto it = std::lower_bound(pagedRefs.begin(), pagedRefs.end(), refNum);
         if (it == pagedRefs.end() || *it != refNum)
@@ -274,7 +274,7 @@ namespace MWWorld
 
     void Scene::removeFromPagedRefs(const Ptr& ptr)
     {
-        const ESM::RefNum& refnum = ptr.getCellRef().getRefNum();
+        ESM::RefNum refnum = ptr.getCellRef().getRefNum();
         if (refnum.hasContentFile() && removeFromSorted(refnum, mPagedRefs))
         {
             if (!ptr.getRefData().getBaseNode())
diff --git a/components/resource/foreachbulletobject.cpp b/components/resource/foreachbulletobject.cpp
index dbad2aea62..b936e39a2a 100644
--- a/components/resource/foreachbulletobject.cpp
+++ b/components/resource/foreachbulletobject.cpp
@@ -79,8 +79,7 @@ namespace Resource
 
             Log(Debug::Debug) << "Loaded " << cellRefs.size() << " cell refs";
 
-            const auto getKey
-                = [](const EsmLoader::Record<CellRef>& v) -> const ESM::RefNum& { return v.mValue.mRefNum; };
+            const auto getKey = [](const EsmLoader::Record<CellRef>& v) -> ESM::RefNum { return v.mValue.mRefNum; };
             std::vector<CellRef> result = prepareRecords(cellRefs, getKey);
 
             Log(Debug::Debug) << "Prepared " << result.size() << " unique cell refs";