diff --git a/Wox.Infrastructure/UserSettings/Settings.cs b/Wox.Infrastructure/UserSettings/Settings.cs
index 73e13a8386..7714768f00 100644
--- a/Wox.Infrastructure/UserSettings/Settings.cs
+++ b/Wox.Infrastructure/UserSettings/Settings.cs
@@ -30,6 +30,7 @@ namespace Wox.Infrastructure.UserSettings
 
         internal StringMatcher.SearchPrecisionScore QuerySearchPrecision { get; private set; } = StringMatcher.SearchPrecisionScore.Regular;
 
+        [JsonIgnore]
         public string QuerySearchPrecisionString
         {
             get { return QuerySearchPrecision.ToString(); }
diff --git a/Wox/App.xaml.cs b/Wox/App.xaml.cs
index 0dbd50abd5..e75f046813 100644
--- a/Wox/App.xaml.cs
+++ b/Wox/App.xaml.cs
@@ -57,7 +57,8 @@ namespace Wox
                 _settings = _settingsVM.Settings;
 
                 _alphabet.Initialize(_settings);
-                StringMatcher.Instance = new StringMatcher(_alphabet);
+                _stringMatcher = new StringMatcher(_alphabet);
+                StringMatcher.Instance = _stringMatcher;
                 _stringMatcher.UserSettingSearchPrecision = _settings.QuerySearchPrecision;
 
                 PluginManager.LoadPlugins(_settings.PluginSettings);