diff --git a/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateJob.kt b/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateJob.kt
index 7053c68ca..e1866b5e9 100755
--- a/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateJob.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateJob.kt
@@ -404,7 +404,7 @@ class LibraryUpdateJob(private val context: Context, workerParams: WorkerParamet
                                                         it.read
                                                     }
                                                     val newReadChapters = this.filter { chapter ->
-                                                        chapter.chapterNumber > 0 &&
+                                                        chapter.chapterNumber >= 0 &&
                                                             readChapters.any {
                                                                 it.chapterNumber == chapter.chapterNumber
                                                             }
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 5b6dee233..08c38292c 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
@@ -700,7 +700,7 @@ class ReaderViewModel @JvmOverloads constructor(
                 // SY <--
                 readerChapter.chapter.read = true
                 // SY -->
-                if (readerChapter.chapter.chapter_number > 0 && readerPreferences.markReadDupe().get()) {
+                if (readerChapter.chapter.chapter_number >= 0 && readerPreferences.markReadDupe().get()) {
                     getChaptersByMangaId.await(manga!!.id).sortedByDescending { it.sourceOrder }
                         .filter {
                             it.id != readerChapter.chapter.id &&