diff --git a/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt b/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
index ed5e8cf9a..1a1851ca1 100644
--- a/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
+++ b/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
@@ -141,6 +141,7 @@ class ThemeConfigFragment : PreferenceFragmentCompat(), SharedPreferences.OnShar
                             AppConfig.isNightTheme = true
                         }
                     }
+                    putPrefInt("defaultTheme", which)
                     App.INSTANCE.applyDayNight()
                     recreateActivities()
                 }