diff --git a/app/src/main/java/eu/kanade/tachiyomi/source/LocalSource.kt b/app/src/main/java/eu/kanade/tachiyomi/source/LocalSource.kt
index 90099cbba3..a0f2c0056b 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/source/LocalSource.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/source/LocalSource.kt
@@ -32,8 +32,6 @@ class LocalSource(private val context: Context) : CatalogueSource {
         private const val COVER_NAME = "cover.jpg"
         private val SUPPORTED_ARCHIVE_TYPES = setOf("zip", "rar", "cbr", "cbz", "epub")
 
-        private val POPULAR_FILTERS = FilterList(OrderBy())
-        private val LATEST_FILTERS = FilterList(OrderBy().apply { state = Filter.Sort.Selection(1, false) })
         private val LATEST_THRESHOLD = TimeUnit.MILLISECONDS.convert(7, TimeUnit.DAYS)
 
         fun updateCover(context: Context, manga: SManga, input: InputStream): File? {
@@ -192,12 +190,10 @@ class LocalSource(private val context: Context) : CatalogueSource {
                     ChapterRecognition.parseChapterNumber(this, manga)
                 }
             }
-            .sortedWith(
-                Comparator { c1, c2 ->
-                    val c = c2.chapter_number.compareTo(c1.chapter_number)
-                    if (c == 0) c2.name.compareToCaseInsensitiveNaturalOrder(c1.name) else c
-                }
-            )
+            .sortedWith { c1, c2 ->
+                val c = c2.chapter_number.compareTo(c1.chapter_number)
+                if (c == 0) c2.name.compareToCaseInsensitiveNaturalOrder(c1.name) else c
+            }
             .toList()
 
         return Observable.just(chapters)
@@ -242,7 +238,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
     }
 
     private fun isSupportedFile(extension: String): Boolean {
-        return extension.toLowerCase() in SUPPORTED_ARCHIVE_TYPES
+        return extension.toLowerCase(Locale.ROOT) in SUPPORTED_ARCHIVE_TYPES
     }
 
     fun getFormat(chapter: SChapter): Format {
@@ -254,7 +250,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
 
             return getFormat(chapFile)
         }
-        throw Exception("Chapter not found")
+        throw Exception(context.getString(R.string.chapter_not_found))
     }
 
     private fun getFormat(file: File): Format {
@@ -268,7 +264,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
         } else if (extension.equals("epub", true)) {
             Format.Epub(file)
         } else {
-            throw Exception("Invalid chapter format")
+            throw Exception(context.getString(R.string.local_invalid_format))
         }
     }
 
@@ -311,9 +307,16 @@ class LocalSource(private val context: Context) : CatalogueSource {
         }
     }
 
-    private class OrderBy : Filter.Sort("Order by", arrayOf("Title", "Date"), Selection(0, true))
+    override fun getFilterList() = POPULAR_FILTERS
 
-    override fun getFilterList() = FilterList(OrderBy())
+    private val POPULAR_FILTERS = FilterList(OrderBy(context))
+    private val LATEST_FILTERS = FilterList(OrderBy(context).apply { state = Filter.Sort.Selection(1, false) })
+
+    private class OrderBy(context: Context) : Filter.Sort(
+        context.getString(R.string.local_filter_order_by),
+        arrayOf(context.getString(R.string.title), context.getString(R.string.date)),
+        Selection(0, true)
+    )
 
     sealed class Format {
         data class Directory(val file: File) : Format()
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 054d8adb77..7395d56bf9 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -519,6 +519,10 @@
     <string name="browse">Browse</string>
     <string name="local_source_help_guide">Local source guide</string>
     <string name="no_pinned_sources">You have no pinned sources</string>
+    <string name="chapter_not_found">Chapter not found</string>
+    <string name="local_invalid_format">Invalid chapter format</string>
+    <string name="local_filter_order_by">Order by</string>
+    <string name="date">Date</string>
 
     <!-- Manga activity -->
     <string name="manga_not_in_db">This manga has been removed from the database.</string>