diff --git a/Flow.Launcher.Core/Plugin/PluginManager.cs b/Flow.Launcher.Core/Plugin/PluginManager.cs
index 5ee723833..6e7b5ec60 100644
--- a/Flow.Launcher.Core/Plugin/PluginManager.cs
+++ b/Flow.Launcher.Core/Plugin/PluginManager.cs
@@ -204,7 +204,7 @@ namespace Flow.Launcher.Core.Plugin
             }
 
             InternationalizationManager.Instance.AddPluginLanguageDirectories(GetPluginsForInterface<IPluginI18n>());
-            InternationalizationManager.Instance.ChangeLanguage(InternationalizationManager.Instance.Settings.Language);
+            InternationalizationManager.Instance.ChangeLanguage(Ioc.Default.GetRequiredService<Settings>().Language);
 
             if (failedPlugins.Any())
             {
diff --git a/Flow.Launcher.Core/Resource/Internationalization.cs b/Flow.Launcher.Core/Resource/Internationalization.cs
index 884276f03..e2a66656a 100644
--- a/Flow.Launcher.Core/Resource/Internationalization.cs
+++ b/Flow.Launcher.Core/Resource/Internationalization.cs
@@ -17,17 +17,18 @@ namespace Flow.Launcher.Core.Resource
 {
     public class Internationalization
     {
-        public Settings Settings { get; set; }
         private const string Folder = "Languages";
         private const string DefaultLanguageCode = "en";
         private const string DefaultFile = "en.xaml";
         private const string Extension = ".xaml";
+        private readonly Settings _settings;
         private readonly List<string> _languageDirectories = new List<string>();
         private readonly List<ResourceDictionary> _oldResources = new List<ResourceDictionary>();
         private readonly string SystemLanguageCode;
 
-        public Internationalization()
+        public Internationalization(Settings settings)
         {
+            _settings = settings;
             AddFlowLauncherLanguageDirectory();
             SystemLanguageCode = GetSystemLanguageCodeAtStartup();
         }
@@ -142,7 +143,7 @@ namespace Flow.Launcher.Core.Resource
             CultureInfo.CurrentUICulture = CultureInfo.CurrentCulture;
 
             // Raise event after culture is set
-            Settings.Language = isSystem ? Constant.SystemLanguageCode : language.LanguageCode;
+            _settings.Language = isSystem ? Constant.SystemLanguageCode : language.LanguageCode;
             _ = Task.Run(() =>
             {
                 UpdatePluginMetadataTranslations();
@@ -153,7 +154,7 @@ namespace Flow.Launcher.Core.Resource
         {
             var languageToSet = GetLanguageByLanguageCode(languageCodeToSet);
 
-            if (Settings.ShouldUsePinyin)
+            if (_settings.ShouldUsePinyin)
                 return false;
 
             if (languageToSet != AvailableLanguages.Chinese && languageToSet != AvailableLanguages.Chinese_TW)
diff --git a/Flow.Launcher.Core/Resource/InternationalizationManager.cs b/Flow.Launcher.Core/Resource/InternationalizationManager.cs
index 3d87626e6..79736edc3 100644
--- a/Flow.Launcher.Core/Resource/InternationalizationManager.cs
+++ b/Flow.Launcher.Core/Resource/InternationalizationManager.cs
@@ -1,26 +1,10 @@
-namespace Flow.Launcher.Core.Resource
+using CommunityToolkit.Mvvm.DependencyInjection;
+
+namespace Flow.Launcher.Core.Resource
 {
     public static class InternationalizationManager
     {
-        private static Internationalization instance;
-        private static object syncObject = new object();
-
         public static Internationalization Instance
-        {
-            get
-            {
-                if (instance == null)
-                {
-                    lock (syncObject)
-                    {
-                        if (instance == null)
-                        {
-                            instance = new Internationalization();
-                        }
-                    }
-                }
-                return instance;
-            }
-        }
+            => Ioc.Default.GetRequiredService<Internationalization>();
     }
-}
\ No newline at end of file
+}
diff --git a/Flow.Launcher.Core/Resource/Theme.cs b/Flow.Launcher.Core/Resource/Theme.cs
index 0c91f69ca..b791915bc 100644
--- a/Flow.Launcher.Core/Resource/Theme.cs
+++ b/Flow.Launcher.Core/Resource/Theme.cs
@@ -25,11 +25,11 @@ namespace Flow.Launcher.Core.Resource
 
         private const int ShadowExtraMargin = 32;
 
-        private readonly IPublicAPI API = Ioc.Default.GetRequiredService<IPublicAPI>();
+        private readonly IPublicAPI API;
+        private readonly Settings Settings;
         private readonly List<string> _themeDirectories = new List<string>();
         private ResourceDictionary _oldResource;
         private string _oldTheme;
-        public Settings Settings { get; set; }
         private const string Folder = Constant.Themes;
         private const string Extension = ".xaml";
         private string DirectoryPath => Path.Combine(Constant.ProgramDirectory, Folder);
@@ -39,8 +39,11 @@ namespace Flow.Launcher.Core.Resource
 
         private double mainWindowWidth;
 
-        public Theme()
+        public Theme(IPublicAPI publicAPI, Settings settings)
         {
+            API = publicAPI;
+            Settings = settings;
+
             _themeDirectories.Add(DirectoryPath);
             _themeDirectories.Add(UserDirectoryPath);
             MakeSureThemeDirectoriesExist();
diff --git a/Flow.Launcher.Core/Resource/ThemeManager.cs b/Flow.Launcher.Core/Resource/ThemeManager.cs
index 71f9acaa5..68cd90a7e 100644
--- a/Flow.Launcher.Core/Resource/ThemeManager.cs
+++ b/Flow.Launcher.Core/Resource/ThemeManager.cs
@@ -1,26 +1,10 @@
-namespace Flow.Launcher.Core.Resource
+using CommunityToolkit.Mvvm.DependencyInjection;
+
+namespace Flow.Launcher.Core.Resource
 {
     public class ThemeManager
     {
-        private static Theme instance;
-        private static object syncObject = new object();
-
         public static Theme Instance
-        {
-            get
-            {
-                if (instance == null)
-                {
-                    lock (syncObject)
-                    {
-                        if (instance == null)
-                        {
-                            instance = new Theme();
-                        }
-                    }
-                }
-                return instance;
-            }
-        }
+            => Ioc.Default.GetRequiredService<Theme>();
     }
 }
diff --git a/Flow.Launcher.Core/Updater.cs b/Flow.Launcher.Core/Updater.cs
index dd0864c19..073084e4d 100644
--- a/Flow.Launcher.Core/Updater.cs
+++ b/Flow.Launcher.Core/Updater.cs
@@ -17,7 +17,6 @@ using Flow.Launcher.Infrastructure.UserSettings;
 using Flow.Launcher.Plugin;
 using System.Text.Json.Serialization;
 using System.Threading;
-using CommunityToolkit.Mvvm.DependencyInjection;
 
 namespace Flow.Launcher.Core
 {
diff --git a/Flow.Launcher/App.xaml.cs b/Flow.Launcher/App.xaml.cs
index b435b566f..c5fe3159f 100644
--- a/Flow.Launcher/App.xaml.cs
+++ b/Flow.Launcher/App.xaml.cs
@@ -50,8 +50,10 @@ namespace Flow.Launcher
                     .AddSingleton<SettingWindowViewModel>()
                     .AddSingleton<IAlphabet, PinyinAlphabet>()
                     .AddSingleton<StringMatcher>()
+                    .AddSingleton<Internationalization>()
                     .AddSingleton<IPublicAPI, PublicAPIInstance>()
                     .AddSingleton<MainViewModel>()
+                    .AddSingleton<Theme>()
                 ).Build();
             Ioc.Default.ConfigureServices(host.Services);
 
@@ -93,7 +95,7 @@ namespace Flow.Launcher
 
                 Ioc.Default.GetRequiredService<StringMatcher>().UserSettingSearchPrecision = _settings.QuerySearchPrecision;
 
-                InternationalizationManager.Instance.Settings = _settings;
+                // TODO: Clean InternationalizationManager.Instance and InternationalizationManager.Instance.GetTranslation in future
                 InternationalizationManager.Instance.ChangeLanguage(_settings.Language);
 
                 PluginManager.LoadPlugins(_settings.PluginSettings);
@@ -114,7 +116,7 @@ namespace Flow.Launcher
                 HotKeyMapper.Initialize(mainVM);
 
                 // main windows needs initialized before theme change because of blur settings
-                ThemeManager.Instance.Settings = _settings;
+                // TODO: Clean ThemeManager.Instance in future
                 ThemeManager.Instance.ChangeTheme(_settings.Theme);
 
                 Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);