diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt
index 960654e072..f3699a62cf 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt
@@ -67,6 +67,7 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
@@ -156,6 +157,11 @@ class ReaderViewModel(
     private var finished = false
     private var chapterToDownload: Download? = null
 
+    private val unfilteredChapterList by lazy {
+        val manga = manga!!
+        runBlocking { getChapter.awaitAll(manga, filterScanlators = false) }
+    }
+
     private lateinit var chapterList: List<ReaderChapter>
 
     private var chapterItems = emptyList<ReaderChapterItem>()
@@ -639,9 +645,8 @@ class ReaderViewModel(
             .contains(LibraryPreferences.MARK_DUPLICATE_READ_CHAPTER_READ_EXISTING)
         if (!markDuplicateAsRead) return
 
-        val duplicateUnreadChapters = chapterList
-            .mapNotNull {
-                val chapter = it.chapter
+        val duplicateUnreadChapters = unfilteredChapterList
+            .mapNotNull { chapter ->
                 if (
                     !chapter.read &&
                     chapter.isRecognizedNumber &&