diff --git a/src/openrct2-ui/windows/Options.cpp b/src/openrct2-ui/windows/Options.cpp
index a65dc60646..96eed6565c 100644
--- a/src/openrct2-ui/windows/Options.cpp
+++ b/src/openrct2-ui/windows/Options.cpp
@@ -40,6 +40,7 @@
 #include <openrct2/localisation/Date.h>
 #include <openrct2/localisation/Language.h>
 #include <openrct2/localisation/Localisation.h>
+#include <openrct2/localisation/LocalisationService.h>
 #include <openrct2/platform/platform.h>
 #include <openrct2/sprites.h>
 #include <openrct2/util/Util.h>
@@ -1150,7 +1151,7 @@ static void window_options_mousedown(rct_window *w, rct_widgetindex widgetIndex,
                 gDropdownItemsArgs[i - 1] = (uintptr_t)LanguagesDescriptors[i].native_name;
             }
             window_options_show_dropdown(w, widget, LANGUAGE_COUNT - 1);
-            dropdown_set_checked(gCurrentLanguage - 1, true);
+            dropdown_set_checked(LocalisationService_GetCurrentLanguage() - 1, true);
             break;
         case WIDX_DATE_FORMAT_DROPDOWN:
             for (size_t i = 0; i < 4; i++) {
@@ -1389,8 +1390,8 @@ static void window_options_dropdown(rct_window *w, rct_widgetindex widgetIndex,
             break;
         case WIDX_LANGUAGE_DROPDOWN:
             {
-                sint32 fallbackLanguage = gCurrentLanguage;
-                if (dropdownIndex != gCurrentLanguage - 1) {
+                auto fallbackLanguage = LocalisationService_GetCurrentLanguage();
+                if (dropdownIndex != LocalisationService_GetCurrentLanguage() - 1) {
                     if (!language_open(dropdownIndex + 1))
                     {
                         // Failed to open language file, try to recover by falling
@@ -1635,7 +1636,7 @@ static void window_options_invalidate(rct_window *w)
 
     case WINDOW_OPTIONS_PAGE_CULTURE:
         // Language
-        set_format_arg(0, char*, LanguagesDescriptors[gCurrentLanguage].native_name);
+        set_format_arg(0, char*, LanguagesDescriptors[LocalisationService_GetCurrentLanguage()].native_name);
 
         // Currency: pounds, dollars, etc. (10 total)
         window_options_culture_widgets[WIDX_CURRENCY].text = CurrencyDescriptors[gConfigGeneral.currency_format].stringId;
diff --git a/src/openrct2/Context.cpp b/src/openrct2/Context.cpp
index e35b840746..c2b5612f90 100644
--- a/src/openrct2/Context.cpp
+++ b/src/openrct2/Context.cpp
@@ -124,7 +124,8 @@ namespace OpenRCT2
             std::shared_ptr<IUiContext> uiContext)
             : _env(env),
               _audioContext(audioContext),
-              _uiContext(uiContext)
+              _uiContext(uiContext),
+              _localisationService(std::make_shared<LocalisationService>(env))
         {
             Instance = this;
         }
@@ -395,14 +396,14 @@ namespace OpenRCT2
             // TODO Ideally we want to delay this until we show the title so that we can
             //      still open the game window and draw a progress screen for the creation
             //      of the object cache.
-            _objectRepository->LoadOrConstruct();
+            _objectRepository->LoadOrConstruct(_localisationService->GetCurrentLanguage());
 
             // TODO Like objects, this can take a while if there are a lot of track designs
             //      its also really something really we might want to do in the background
             //      as its not required until the player wants to place a new ride.
-            _trackDesignRepository->Scan();
+            _trackDesignRepository->Scan(_localisationService->GetCurrentLanguage());
 
-            _scenarioRepository->Scan();
+            _scenarioRepository->Scan(_localisationService->GetCurrentLanguage());
             TitleSequenceManager::Scan();
 
             if (!gOpenRCT2Headless)
diff --git a/src/openrct2/cmdline/RootCommands.cpp b/src/openrct2/cmdline/RootCommands.cpp
index 16841f7a8e..2b864c82ac 100644
--- a/src/openrct2/cmdline/RootCommands.cpp
+++ b/src/openrct2/cmdline/RootCommands.cpp
@@ -400,11 +400,7 @@ static exitcode_t HandleCommandScanObjects([[maybe_unused]] CommandLineArgEnumer
     auto context = std::unique_ptr<OpenRCT2::IContext>(OpenRCT2::CreateContext());
     auto env = context->GetPlatformEnvironment();
     auto objectRepository = CreateObjectRepository(env);
-
-    // HACK: set gCurrentLanguage otherwise it be wrong for the index file
-    gCurrentLanguage = gConfigGeneral.language;
-
-    objectRepository->Construct();
+    objectRepository->Construct(gConfigGeneral.language);
     return EXITCODE_OK;
 }
 
diff --git a/src/openrct2/core/FileIndex.hpp b/src/openrct2/core/FileIndex.hpp
index f834e4f2ee..99adbf1bbf 100644
--- a/src/openrct2/core/FileIndex.hpp
+++ b/src/openrct2/core/FileIndex.hpp
@@ -107,11 +107,11 @@ public:
      * Queries and directories and loads the index header. If the index is up to date,
      * the items are loaded from the index and returned, otherwise the index is rebuilt.
      */
-    std::vector<TItem> LoadOrBuild() const
+    std::vector<TItem> LoadOrBuild(sint32 language) const
     {
         std::vector<TItem> items;
         auto scanResult = Scan();
-        auto readIndexResult = ReadIndexFile(scanResult.Stats);
+        auto readIndexResult = ReadIndexFile(language, scanResult.Stats);
         if (std::get<0>(readIndexResult))
         {
             // Index was loaded
@@ -120,15 +120,15 @@ public:
         else
         {
             // Index was not loaded
-            items = Build(scanResult);
+            items = Build(language, scanResult);
         }
         return items;
     }
 
-    std::vector<TItem> Rebuild() const
+    std::vector<TItem> Rebuild(sint32 language) const
     {
         auto scanResult = Scan();
-        auto items = Build(scanResult);
+        auto items = Build(language, scanResult);
         return items;
     }
 
@@ -208,7 +208,7 @@ private:
         }
     }
 
-    std::vector<TItem> Build(const ScanResult &scanResult) const
+    std::vector<TItem> Build(sint32 language, const ScanResult &scanResult) const
     {
         std::vector<TItem> allItems;
         Console::WriteLine("Building %s (%zu items)", _name.c_str(), scanResult.Files.size());
@@ -262,7 +262,7 @@ private:
                 allItems.insert(allItems.end(), itr.begin(), itr.end());
             }
 
-            WriteIndexFile(scanResult.Stats, allItems);
+            WriteIndexFile(language, scanResult.Stats, allItems);
         }
 
         auto endTime = std::chrono::high_resolution_clock::now();
@@ -272,7 +272,7 @@ private:
         return allItems;
     }
 
-    std::tuple<bool, std::vector<TItem>> ReadIndexFile(const DirectoryStats &stats) const
+    std::tuple<bool, std::vector<TItem>> ReadIndexFile(sint32 language, const DirectoryStats &stats) const
     {
         bool loadedItems = false;
         std::vector<TItem> items;
@@ -289,7 +289,7 @@ private:
                     header.MagicNumber == _magicNumber &&
                     header.VersionA == FILE_INDEX_VERSION &&
                     header.VersionB == _version &&
-                    header.LanguageId == gCurrentLanguage &&
+                    header.LanguageId == language &&
                     header.Stats.TotalFiles == stats.TotalFiles &&
                     header.Stats.TotalFileSize == stats.TotalFileSize &&
                     header.Stats.FileDateModifiedChecksum == stats.FileDateModifiedChecksum &&
@@ -318,7 +318,7 @@ private:
         return std::make_tuple(loadedItems, items);
     }
 
-    void WriteIndexFile(const DirectoryStats &stats, const std::vector<TItem> &items) const
+    void WriteIndexFile(sint32 language, const DirectoryStats &stats, const std::vector<TItem> &items) const
     {
         try
         {
@@ -331,7 +331,7 @@ private:
             header.MagicNumber = _magicNumber;
             header.VersionA = FILE_INDEX_VERSION;
             header.VersionB = _version;
-            header.LanguageId = gCurrentLanguage;
+            header.LanguageId = language;
             header.Stats = stats;
             header.NumItems = (uint32)items.size();
             fs.WriteValue(header);
diff --git a/src/openrct2/interface/Fonts.cpp b/src/openrct2/interface/Fonts.cpp
index f63832a736..5e58ac578c 100644
--- a/src/openrct2/interface/Fonts.cpp
+++ b/src/openrct2/interface/Fonts.cpp
@@ -148,7 +148,8 @@ static bool LoadCustomConfigFont(LocalisationService& localisationService)
 void TryLoadFonts(LocalisationService& localisationService)
 {
 #ifndef NO_TTF
-    TTFontFamily const * fontFamily = LanguagesDescriptors[gCurrentLanguage].font_family;
+    auto currentLanguage = localisationService.GetCurrentLanguage();
+    TTFontFamily const * fontFamily = LanguagesDescriptors[currentLanguage].font_family;
 
     if (fontFamily != FAMILY_OPENRCT2_SPRITE)
     {
diff --git a/src/openrct2/localisation/Language.h b/src/openrct2/localisation/Language.h
index 1e20175715..e2b77ba462 100644
--- a/src/openrct2/localisation/Language.h
+++ b/src/openrct2/localisation/Language.h
@@ -86,8 +86,6 @@ struct language_descriptor {
 
 extern const language_descriptor LanguagesDescriptors[LANGUAGE_COUNT];
 
-extern sint32 gCurrentLanguage;
-
 extern const utf8 BlackUpArrowString[];
 extern const utf8 BlackDownArrowString[];
 extern const utf8 BlackLeftArrowString[];
diff --git a/src/openrct2/localisation/LocalisationService.cpp b/src/openrct2/localisation/LocalisationService.cpp
index ee08e1b75d..8f988577fd 100644
--- a/src/openrct2/localisation/LocalisationService.cpp
+++ b/src/openrct2/localisation/LocalisationService.cpp
@@ -40,6 +40,11 @@ LocalisationService::LocalisationService(const std::shared_ptr<IPlatformEnvironm
     }
 }
 
+// Define implementation here to avoid including LanguagePack.h in header
+LocalisationService::~LocalisationService()
+{
+}
+
 const char * LocalisationService::GetString(rct_string_id id) const
 {
     const char * result = nullptr;
@@ -69,7 +74,7 @@ std::string LocalisationService::GetLanguagePath(uint32 languageId) const
 {
     auto locale = std::string(LanguagesDescriptors[languageId].locale);
     auto languageDirectory = _env->GetDirectoryPath(DIRBASE::OPENRCT2, DIRID::LANGUAGE);
-    auto languagePath = Path::Combine(languageDirectory, locale + "txt");
+    auto languagePath = Path::Combine(languageDirectory, locale + ".txt");
     return languagePath;
 }
 
@@ -98,8 +103,10 @@ void LocalisationService::OpenLanguage(sint32 id, IObjectManager& objectManager)
         // Objects and their localised strings need to be refreshed
         objectManager.ResetObjects();
     }
-
-    throw std::runtime_error("Unable to open language " + std::to_string(id));
+    else
+    {
+        throw std::runtime_error("Unable to open language " + std::to_string(id));
+    }
 }
 
 void LocalisationService::CloseLanguages()
diff --git a/src/openrct2/localisation/LocalisationService.h b/src/openrct2/localisation/LocalisationService.h
index 11b04c51c8..e7017aad22 100644
--- a/src/openrct2/localisation/LocalisationService.h
+++ b/src/openrct2/localisation/LocalisationService.h
@@ -46,6 +46,7 @@ namespace OpenRCT2::Localisation
         void UseTrueTypeFont(bool value) { _useTrueTypeFont = value; }
 
         LocalisationService(const std::shared_ptr<IPlatformEnvironment>& env);
+        ~LocalisationService();
 
         const char * GetString(rct_string_id id) const;
         std::tuple<rct_string_id, rct_string_id, rct_string_id> GetLocalisedScenarioStrings(const std::string& scenarioFilename) const;
diff --git a/src/openrct2/object/ObjectRepository.cpp b/src/openrct2/object/ObjectRepository.cpp
index c29cc1401a..95eb256f63 100644
--- a/src/openrct2/object/ObjectRepository.cpp
+++ b/src/openrct2/object/ObjectRepository.cpp
@@ -43,6 +43,7 @@
 
 #include "../config/Config.h"
 #include "../localisation/Localisation.h"
+#include "../localisation/LocalisationService.h"
 #include "../object/Object.h"
 #include "ObjectList.h"
 #include "../platform/platform.h"
@@ -225,17 +226,17 @@ public:
         ClearItems();
     }
 
-    void LoadOrConstruct() override
+    void LoadOrConstruct(sint32 language) override
     {
         ClearItems();
-        auto items = _fileIndex.LoadOrBuild();
+        auto items = _fileIndex.LoadOrBuild(language);
         AddItems(items);
         SortItems();
     }
 
-    void Construct() override
+    void Construct(sint32 language) override
     {
-        auto items = _fileIndex.Rebuild();
+        auto items = _fileIndex.Rebuild(language);
         AddItems(items);
         SortItems();
     }
@@ -665,8 +666,9 @@ const rct_object_entry * object_list_find(rct_object_entry * entry)
 void object_list_load()
 {
     auto context = GetContext();
-    IObjectRepository * objectRepository = context->GetObjectRepository();
-    objectRepository->LoadOrConstruct();
+    const auto localisationService = context->GetLocalisationService();
+    auto objectRepository = context->GetObjectRepository();
+    objectRepository->LoadOrConstruct(localisationService->GetCurrentLanguage());
 
     IObjectManager * objectManager = context->GetObjectManager();
     objectManager->UnloadAll();
diff --git a/src/openrct2/object/ObjectRepository.h b/src/openrct2/object/ObjectRepository.h
index 2e62a595bd..1d71b20e02 100644
--- a/src/openrct2/object/ObjectRepository.h
+++ b/src/openrct2/object/ObjectRepository.h
@@ -29,6 +29,11 @@ namespace OpenRCT2
     interface IPlatformEnvironment;
 }
 
+namespace OpenRCT2::Localisation
+{
+    class LocalisationService;
+}
+
 struct rct_drawpixelinfo;
 
 struct ObjectRepositoryItem
@@ -59,8 +64,8 @@ interface IObjectRepository
 {
     virtual ~IObjectRepository() = default;
 
-    virtual void                            LoadOrConstruct() abstract;
-    virtual void                            Construct() abstract;
+    virtual void                            LoadOrConstruct(sint32 language) abstract;
+    virtual void                            Construct(sint32 language) abstract;
     virtual size_t                          GetNumObjects() const abstract;
     virtual const ObjectRepositoryItem *    GetObjects() const abstract;
     virtual const ObjectRepositoryItem *    FindObject(const utf8 * name) const abstract;
diff --git a/src/openrct2/object/StringTable.cpp b/src/openrct2/object/StringTable.cpp
index cc1a5568b5..33d0ae26e7 100644
--- a/src/openrct2/object/StringTable.cpp
+++ b/src/openrct2/object/StringTable.cpp
@@ -19,6 +19,7 @@
 #include "../core/String.hpp"
 #include "../localisation/Language.h"
 #include "../localisation/LanguagePack.h"
+#include "../localisation/LocalisationService.h"
 #include "Object.h"
 #include "StringTable.h"
 
@@ -111,7 +112,8 @@ void StringTable::SetString(uint8 id, uint8 language, const std::string &text)
 
 void StringTable::Sort()
 {
-    std::sort(_strings.begin(), _strings.end(), [](const StringTableEntry &a, const StringTableEntry &b) -> bool
+    auto targetLanguage = LocalisationService_GetCurrentLanguage();
+    std::sort(_strings.begin(), _strings.end(), [targetLanguage](const StringTableEntry &a, const StringTableEntry &b) -> bool
     {
         if (a.Id == b.Id)
         {
@@ -120,11 +122,11 @@ void StringTable::Sort()
                 return String::Compare(a.Text, b.Text, true) < 0;
             }
 
-            if (a.LanguageId == gCurrentLanguage)
+            if (a.LanguageId == targetLanguage)
             {
                 return true;
             }
-            if (b.LanguageId == gCurrentLanguage)
+            if (b.LanguageId == targetLanguage)
             {
                 return false;
             }
diff --git a/src/openrct2/ride/TrackDesignRepository.cpp b/src/openrct2/ride/TrackDesignRepository.cpp
index b2e61d5f9e..c105e1a478 100644
--- a/src/openrct2/ride/TrackDesignRepository.cpp
+++ b/src/openrct2/ride/TrackDesignRepository.cpp
@@ -26,6 +26,7 @@
 #include "../core/FileStream.hpp"
 #include "../core/Path.hpp"
 #include "../core/String.hpp"
+#include "../localisation/LocalisationService.h"
 #include "../object/ObjectRepository.h"
 #include "../object/RideObject.h"
 #include "../PlatformEnvironment.h"
@@ -284,10 +285,10 @@ public:
         return refs;
     }
 
-    void Scan() override
+    void Scan(sint32 language) override
     {
         _items.clear();
-        auto trackDesigns = _fileIndex.LoadOrBuild();
+        auto trackDesigns = _fileIndex.LoadOrBuild(language);
         for (const auto &td : trackDesigns)
         {
             _items.push_back(td);
@@ -404,7 +405,7 @@ ITrackDesignRepository * CreateTrackDesignRepository(std::shared_ptr<IPlatformEn
 void track_repository_scan()
 {
     ITrackDesignRepository * repo = GetContext()->GetTrackDesignRepository();
-    repo->Scan();
+    repo->Scan(LocalisationService_GetCurrentLanguage());
 }
 
 bool track_repository_delete(const utf8 * path)
diff --git a/src/openrct2/ride/TrackDesignRepository.h b/src/openrct2/ride/TrackDesignRepository.h
index c5d09129bd..7426f149d4 100644
--- a/src/openrct2/ride/TrackDesignRepository.h
+++ b/src/openrct2/ride/TrackDesignRepository.h
@@ -46,7 +46,7 @@ interface ITrackDesignRepository
     virtual std::vector<track_design_file_ref> GetItemsForRideGroup(uint8 rideType,
                                                                     const RideGroup * rideGroup) const abstract;
 
-    virtual void Scan() abstract;
+    virtual void Scan(sint32 language) abstract;
     virtual bool Delete(const std::string &path) abstract;
     virtual std::string Rename(const std::string &path, const std::string &newName) abstract;
     virtual std::string Install(const std::string &path) abstract;
diff --git a/src/openrct2/scenario/ScenarioRepository.cpp b/src/openrct2/scenario/ScenarioRepository.cpp
index 2992a65796..b02cddbcad 100644
--- a/src/openrct2/scenario/ScenarioRepository.cpp
+++ b/src/openrct2/scenario/ScenarioRepository.cpp
@@ -33,6 +33,7 @@
 
 #include "../config/Config.h"
 #include "../localisation/Localisation.h"
+#include "../localisation/LocalisationService.h"
 #include "../platform/platform.h"
 #include "Scenario.h"
 #include "../Game.h"
@@ -339,13 +340,13 @@ public:
         ClearHighscores();
     }
 
-    void Scan() override
+    void Scan(sint32 language) override
     {
         ImportMegaPark();
 
         // Reload scenarios from index
         _scenarios.clear();
-        auto scenarios = _fileIndex.LoadOrBuild();
+        auto scenarios = _fileIndex.LoadOrBuild(language);
         for (auto scenario : scenarios)
         {
             AddScenario(scenario);
@@ -415,11 +416,11 @@ public:
         return nullptr;
     }
 
-    bool TryRecordHighscore(const utf8 * scenarioFileName, money32 companyValue, const utf8 * name) override
+    bool TryRecordHighscore(sint32 language, const utf8 * scenarioFileName, money32 companyValue, const utf8 * name) override
     {
         // Scan the scenarios so we have a fresh list to query. This is to prevent the issue of scenario completions
         // not getting recorded, see #4951.
-        Scan();
+        Scan(language);
 
         scenario_index_entry * scenario = GetByFilename(scenarioFileName);
         if (scenario != nullptr)
@@ -743,7 +744,7 @@ IScenarioRepository * GetScenarioRepository()
 void scenario_repository_scan()
 {
     IScenarioRepository * repo = GetScenarioRepository();
-    repo->Scan();
+    repo->Scan(LocalisationService_GetCurrentLanguage());
 }
 
 size_t scenario_repository_get_count()
@@ -761,6 +762,6 @@ const scenario_index_entry *scenario_repository_get_by_index(size_t index)
 bool scenario_repository_try_record_highscore(const utf8 * scenarioFileName, money32 companyValue, const utf8 * name)
 {
     IScenarioRepository * repo = GetScenarioRepository();
-    return repo->TryRecordHighscore(scenarioFileName, companyValue, name);
+    return repo->TryRecordHighscore(LocalisationService_GetCurrentLanguage(), scenarioFileName, companyValue, name);
 }
 
diff --git a/src/openrct2/scenario/ScenarioRepository.h b/src/openrct2/scenario/ScenarioRepository.h
index 90e4c912c7..5baea19768 100644
--- a/src/openrct2/scenario/ScenarioRepository.h
+++ b/src/openrct2/scenario/ScenarioRepository.h
@@ -64,7 +64,7 @@ interface IScenarioRepository
     /**
      * Scans the scenario directories and grabs the metadata for all the scenarios.
      */
-    virtual void Scan() abstract;
+    virtual void Scan(sint32 language) abstract;
 
     virtual size_t GetCount() const abstract;
     virtual const scenario_index_entry * GetByIndex(size_t index) const  abstract;
@@ -75,7 +75,7 @@ interface IScenarioRepository
     virtual const scenario_index_entry * GetByInternalName(const utf8 * name) const abstract;
     virtual const scenario_index_entry * GetByPath(const utf8 * path) const abstract;
 
-    virtual bool TryRecordHighscore(const utf8 * scenarioFileName, money32 companyValue, const utf8 * name) abstract;
+    virtual bool TryRecordHighscore(sint32 language, const utf8 * scenarioFileName, money32 companyValue, const utf8 * name) abstract;
 };
 
 IScenarioRepository * CreateScenarioRepository(std::shared_ptr<OpenRCT2::IPlatformEnvironment> env);