diff --git a/LunaTranslator/LunaTranslator/gui/settin.py b/LunaTranslator/LunaTranslator/gui/settin.py
index cc0fbb43..da4b3045 100644
--- a/LunaTranslator/LunaTranslator/gui/settin.py
+++ b/LunaTranslator/LunaTranslator/gui/settin.py
@@ -252,6 +252,8 @@ class Settin(closeashidewindow):
             dark = True
         elif dl == 2:
             dark = darkdetect.isDark()
+            if dark is None:
+                dark = False
         darklight = ["light", "dark"][dark]
 
         class WindowEventFilter(QObject):