diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1276a449f0..fbc6c30adb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@
     Bug #6992: Crossbow reloading doesn't look the same as in Morrowind
     Bug #6993: Shooting your last round of ammunition causes the attack animation to cancel
     Bug #7009: Falling actors teleport to the ground without receiving any damage on cell loading
+    Bug #7034: Misc items defined in one content file are not treated as keys if another content file uses them as such
     Feature #6933: Support high-resolution cursor textures
     Feature #6945: Support S3TC-compressed and BGR/BGRA NiPixelData
     Feature #6979: Add support of loading and displaying LOD assets purely based on their filename extension
diff --git a/apps/esmtool/record.cpp b/apps/esmtool/record.cpp
index 78c55343c4..78b14d4894 100644
--- a/apps/esmtool/record.cpp
+++ b/apps/esmtool/record.cpp
@@ -1042,7 +1042,7 @@ namespace EsmTool
             std::cout << "  Script: " << mData.mScript << std::endl;
         std::cout << "  Weight: " << mData.mData.mWeight << std::endl;
         std::cout << "  Value: " << mData.mData.mValue << std::endl;
-        std::cout << "  Is Key: " << mData.mData.mIsKey << std::endl;
+        std::cout << "  Is Key: " << (mData.mData.mFlags & ESM::Miscellaneous::Key) << std::endl;
         std::cout << "  Deleted: " << mIsDeleted << std::endl;
     }
 
diff --git a/apps/opencs/model/world/refidadapterimp.cpp b/apps/opencs/model/world/refidadapterimp.cpp
index 54917fd0d9..4e9c5d3c78 100644
--- a/apps/opencs/model/world/refidadapterimp.cpp
+++ b/apps/opencs/model/world/refidadapterimp.cpp
@@ -726,7 +726,7 @@ QVariant CSMWorld::MiscRefIdAdapter::getData(const RefIdColumn* column, const Re
         data.getRecord(RefIdData::LocalIndex(index, UniversalId::Type_Miscellaneous)));
 
     if (column == mKey)
-        return record.get().mData.mIsKey != 0;
+        return bool(record.get().mData.mFlags & ESM::Miscellaneous::Key);
 
     return InventoryRefIdAdapter<ESM::Miscellaneous>::getData(column, data, index);
 }
@@ -740,7 +740,7 @@ void CSMWorld::MiscRefIdAdapter::setData(
     ESM::Miscellaneous misc = record.get();
 
     if (column == mKey)
-        misc.mData.mIsKey = value.toInt();
+        misc.mData.mFlags = value.toInt();
     else
     {
         InventoryRefIdAdapter<ESM::Miscellaneous>::setData(column, data, index, value);
diff --git a/apps/openmw/mwclass/misc.cpp b/apps/openmw/mwclass/misc.cpp
index 8ddf6f6522..c0b9ecdd8f 100644
--- a/apps/openmw/mwclass/misc.cpp
+++ b/apps/openmw/mwclass/misc.cpp
@@ -155,7 +155,7 @@ namespace MWClass
         std::string text;
 
         text += MWGui::ToolTips::getWeightString(ref->mBase->mData.mWeight, "#{sWeight}");
-        if (!gold && !ref->mBase->mData.mIsKey)
+        if (!gold && !(ref->mBase->mData.mFlags & ESM::Miscellaneous::Key))
             text += MWGui::ToolTips::getValueString(getValue(ptr), "#{sValue}");
 
         if (MWBase::Environment::get().getWindowManager()->getFullHelp())
@@ -221,7 +221,7 @@ namespace MWClass
     {
         const MWWorld::LiveCellRef<ESM::Miscellaneous>* ref = item.get<ESM::Miscellaneous>();
 
-        return !ref->mBase->mData.mIsKey && (npcServices & ESM::NPC::Misc) && !isGold(item);
+        return !(ref->mBase->mData.mFlags & ESM::Miscellaneous::Key) && (npcServices & ESM::NPC::Misc) && !isGold(item);
     }
 
     float Miscellaneous::getWeight(const MWWorld::ConstPtr& ptr) const
@@ -233,7 +233,7 @@ namespace MWClass
     bool Miscellaneous::isKey(const MWWorld::ConstPtr& ptr) const
     {
         const MWWorld::LiveCellRef<ESM::Miscellaneous>* ref = ptr.get<ESM::Miscellaneous>();
-        return ref->mBase->mData.mIsKey != 0;
+        return ref->mBase->mData.mFlags & ESM::Miscellaneous::Key;
     }
 
     bool Miscellaneous::isSoulGem(const MWWorld::ConstPtr& ptr) const
diff --git a/apps/openmw/mwlua/types/misc.cpp b/apps/openmw/mwlua/types/misc.cpp
index 0b3f66a327..cfb2a89ad5 100644
--- a/apps/openmw/mwlua/types/misc.cpp
+++ b/apps/openmw/mwlua/types/misc.cpp
@@ -42,8 +42,8 @@ namespace MWLua
         record["icon"] = sol::readonly_property([vfs](const ESM::Miscellaneous& rec) -> std::string {
             return Misc::ResourceHelpers::correctIconPath(rec.mIcon, vfs);
         });
-        record["isKey"]
-            = sol::readonly_property([](const ESM::Miscellaneous& rec) -> bool { return rec.mData.mIsKey; });
+        record["isKey"] = sol::readonly_property(
+            [](const ESM::Miscellaneous& rec) -> bool { return rec.mData.mFlags & ESM::Miscellaneous::Key; });
         record["value"] = sol::readonly_property([](const ESM::Miscellaneous& rec) -> int { return rec.mData.mValue; });
         record["weight"]
             = sol::readonly_property([](const ESM::Miscellaneous& rec) -> float { return rec.mData.mWeight; });
diff --git a/apps/openmw/mwworld/esmstore.cpp b/apps/openmw/mwworld/esmstore.cpp
index 3fd5980abe..520b60abf6 100644
--- a/apps/openmw/mwworld/esmstore.cpp
+++ b/apps/openmw/mwworld/esmstore.cpp
@@ -34,8 +34,8 @@ namespace
 
     constexpr std::size_t deletedRefID = std::numeric_limits<std::size_t>::max();
 
-    void readRefs(
-        const ESM::Cell& cell, std::vector<Ref>& refs, std::vector<std::string>& refIDs, ESM::ReadersCache& readers)
+    void readRefs(const ESM::Cell& cell, std::vector<Ref>& refs, std::vector<std::string>& refIDs,
+        std::set<std::string, Misc::StringUtils::CiComp>& keyIDs, ESM::ReadersCache& readers)
     {
         // TODO: we have many similar copies of this code.
         for (size_t i = 0; i < cell.mContextList.size(); i++)
@@ -53,6 +53,8 @@ namespace
                 else if (std::find(cell.mMovedRefs.begin(), cell.mMovedRefs.end(), ref.mRefNum)
                     == cell.mMovedRefs.end())
                 {
+                    if (!ref.mKey.empty())
+                        keyIDs.insert(std::move(ref.mKey));
                     refs.emplace_back(ref.mRefNum, refIDs.size());
                     refIDs.push_back(std::move(ref.mRefID));
                 }
@@ -64,6 +66,8 @@ namespace
                 refs.emplace_back(value.mRefNum, deletedRefID);
             else
             {
+                if (!value.mKey.empty())
+                    keyIDs.insert(std::move(value.mKey));
                 refs.emplace_back(value.mRefNum, refIDs.size());
                 refIDs.push_back(value.mRefID);
             }
@@ -403,10 +407,10 @@ namespace MWWorld
     void ESMStore::validateRecords(ESM::ReadersCache& readers)
     {
         validate();
-        countAllCellRefs(readers);
+        countAllCellRefsAndMarkKeys(readers);
     }
 
-    void ESMStore::countAllCellRefs(ESM::ReadersCache& readers)
+    void ESMStore::countAllCellRefsAndMarkKeys(ESM::ReadersCache& readers)
     {
         // TODO: We currently need to read entire files here again.
         // We should consider consolidating or deferring this reading.
@@ -414,11 +418,12 @@ namespace MWWorld
             return;
         std::vector<Ref> refs;
         std::vector<std::string> refIDs;
-        Store<ESM::Cell> Cells = getWritable<ESM::Cell>();
+        std::set<std::string, Misc::StringUtils::CiComp> keyIDs;
+        Store<ESM::Cell> Cells = get<ESM::Cell>();
         for (auto it = Cells.intBegin(); it != Cells.intEnd(); ++it)
-            readRefs(*it, refs, refIDs, readers);
+            readRefs(*it, refs, refIDs, keyIDs, readers);
         for (auto it = Cells.extBegin(); it != Cells.extEnd(); ++it)
-            readRefs(*it, refs, refIDs, readers);
+            readRefs(*it, refs, refIDs, keyIDs, readers);
         const auto lessByRefNum = [](const Ref& l, const Ref& r) { return l.mRefNum < r.mRefNum; };
         std::stable_sort(refs.begin(), refs.end(), lessByRefNum);
         const auto equalByRefNum = [](const Ref& l, const Ref& r) { return l.mRefNum == r.mRefNum; };
@@ -432,6 +437,13 @@ namespace MWWorld
             }
         };
         Misc::forEachUnique(refs.rbegin(), refs.rend(), equalByRefNum, incrementRefCount);
+        auto& store = getWritable<ESM::Miscellaneous>().mStatic;
+        for (const std::string& id : keyIDs)
+        {
+            auto it = store.find(id);
+            if (it != store.end())
+                it->second.mData.mFlags |= ESM::Miscellaneous::Key;
+        }
     }
 
     int ESMStore::getRefCount(std::string_view id) const
diff --git a/apps/openmw/mwworld/esmstore.hpp b/apps/openmw/mwworld/esmstore.hpp
index d41312ac4e..a4a714af91 100644
--- a/apps/openmw/mwworld/esmstore.hpp
+++ b/apps/openmw/mwworld/esmstore.hpp
@@ -125,7 +125,7 @@ namespace MWWorld
         /// Validate entries in store after setup
         void validate();
 
-        void countAllCellRefs(ESM::ReadersCache& readers);
+        void countAllCellRefsAndMarkKeys(ESM::ReadersCache& readers);
 
         template <class T>
         void removeMissingObjects(Store<T>& store);
diff --git a/components/esm3/loadmisc.cpp b/components/esm3/loadmisc.cpp
index 6e0ed03b22..74022b2e99 100644
--- a/components/esm3/loadmisc.cpp
+++ b/components/esm3/loadmisc.cpp
@@ -75,7 +75,7 @@ namespace ESM
         mRecordFlags = 0;
         mData.mWeight = 0;
         mData.mValue = 0;
-        mData.mIsKey = 0;
+        mData.mFlags = 0;
         mName.clear();
         mModel.clear();
         mIcon.clear();
diff --git a/components/esm3/loadmisc.hpp b/components/esm3/loadmisc.hpp
index 7a203443cf..ddd0561c6b 100644
--- a/components/esm3/loadmisc.hpp
+++ b/components/esm3/loadmisc.hpp
@@ -27,10 +27,14 @@ namespace ESM
         {
             float mWeight;
             int mValue;
-            int mIsKey; // There are many keys in Morrowind.esm that has this
-                        // set to 0. TODO: Check what this field corresponds to
-                        // in the editor.
+            int mFlags;
         };
+
+        enum Flags
+        {
+            Key = 0x1 // Assigned as a key in the content file that defined the record
+        };
+
         MCDTstruct mData;
 
         unsigned int mRecordFlags;