diff --git a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSorter.kt b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSorter.kt
index 764f00491c..a069a2c7c4 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSorter.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSorter.kt
@@ -2,7 +2,6 @@ package eu.kanade.tachiyomi.util.chapter
 
 import eu.kanade.tachiyomi.data.database.models.Chapter
 import eu.kanade.tachiyomi.data.database.models.Manga
-import eu.kanade.tachiyomi.util.lang.compareToCaseInsensitiveNaturalOrder
 
 fun getChapterSort(manga: Manga, sortDescending: Boolean = manga.sortDescending()): (Chapter, Chapter) -> Int {
     return when (manga.sorting) {
@@ -11,13 +10,13 @@ fun getChapterSort(manga: Manga, sortDescending: Boolean = manga.sortDescending(
             false -> { c1, c2 -> c2.source_order.compareTo(c1.source_order) }
         }
         Manga.CHAPTER_SORTING_NUMBER -> when (sortDescending) {
-            true -> { c1, c2 -> c2.chapter_number.toString().compareToCaseInsensitiveNaturalOrder(c1.chapter_number.toString()) }
-            false -> { c1, c2 -> c1.chapter_number.toString().compareToCaseInsensitiveNaturalOrder(c2.chapter_number.toString()) }
+            true -> { c1, c2 -> c2.chapter_number.compareTo(c1.chapter_number) }
+            false -> { c1, c2 -> c1.chapter_number.compareTo(c2.chapter_number) }
         }
         Manga.CHAPTER_SORTING_UPLOAD_DATE -> when (sortDescending) {
             true -> { c1, c2 -> c2.date_upload.compareTo(c1.date_upload) }
             false -> { c1, c2 -> c1.date_upload.compareTo(c2.date_upload) }
         }
-        else -> throw NotImplementedError("Unimplemented sorting method")
+        else -> throw NotImplementedError("Invalid chapter sorting method: ${manga.sorting}")
     }
 }
diff --git a/app/src/test/java/eu/kanade/tachiyomi/data/database/ChapterRecognitionTest.kt b/app/src/test/java/eu/kanade/tachiyomi/data/database/ChapterRecognitionTest.kt
index 6b92a002aa..c1bcb66744 100644
--- a/app/src/test/java/eu/kanade/tachiyomi/data/database/ChapterRecognitionTest.kt
+++ b/app/src/test/java/eu/kanade/tachiyomi/data/database/ChapterRecognitionTest.kt
@@ -258,4 +258,4 @@ class ChapterRecognitionTest {
         val chapterNumber = parseChapterNumber(mangaTitle, name)
         assertEquals(chapterNumber, expected)
     }
-}
\ No newline at end of file
+}