src/Domain/Manga/Application/QueryHandler/GetMangaChaptersHandler.php

@@ -103,7 +103,9 @@ readonly class GetMangaChaptersHandler
         $min = min($numbers);
         $max = max($numbers);
 
-        $fmt = fn (float $n) => $n == (int) $n ? (string) (int) $n : (string) $n;
+        $fmt = fn (float $n) => $n == (int) $n
+            ? str_pad((string) (int) $n, 2, '0', STR_PAD_LEFT)
+            : (string) $n;
         $range = count($group) > 1 ? $fmt($min).'-'.$fmt($max) : $fmt($min);
 
         return new ChapterResponse(