diff --git a/app/src/main/java/io/legado/app/ui/readbook/ReadMenu.kt b/app/src/main/java/io/legado/app/ui/readbook/ReadMenu.kt
index 45442dc66..b15272816 100644
--- a/app/src/main/java/io/legado/app/ui/readbook/ReadMenu.kt
+++ b/app/src/main/java/io/legado/app/ui/readbook/ReadMenu.kt
@@ -99,7 +99,7 @@ class ReadMenu : FrameLayout {
         seek_read_page.progress = dur
     }
 
-    fun brightnessAuto(): Boolean {
+    private fun brightnessAuto(): Boolean {
         return context.getPrefBoolean("brightnessAuto", true)
     }