diff --git a/src/BiliLite.UWP/Services/ThemeService.cs b/src/BiliLite.UWP/Services/ThemeService.cs
index 24272bc4a..c5a65a02f 100644
--- a/src/BiliLite.UWP/Services/ThemeService.cs
+++ b/src/BiliLite.UWP/Services/ThemeService.cs
@@ -16,7 +16,7 @@ public ThemeService()
             m_theme = (ElementTheme)SettingService.GetValue<int>(SettingConstants.UI.THEME, 0);
             if (m_theme == ElementTheme.Default)
             {
-                m_theme = (ElementTheme)(App.Current.RequestedTheme - 1);
+                m_theme = (ElementTheme)(App.Current.RequestedTheme + 1);
             }
         }