diff --git a/nhentai/doujinshi.py b/nhentai/doujinshi.py
index 6d5b84f..dcd3dc2 100644
--- a/nhentai/doujinshi.py
+++ b/nhentai/doujinshi.py
@@ -74,24 +74,23 @@ class Doujinshi(object):
 
     def check_if_need_download(self, options):
         base_path = os.path.join(self.downloader.path, self.filename)
-        file_ext = None
 
         # regenerate, re-download
         if options.regenerate:
             return True
 
-        # detect file extensions
-        if options.is_pdf:
-            file_ext = 'pdf'
-        elif options.is_cbz:
-            file_ext = 'cbz'
-
         # pdf or cbz file exists, skip re-download
         # doujinshi directory may not exist b/c of --rm-origin-dir option set.
         # user should pass --regenerate option to get back origin dir.
-        if file_ext is not None:
-            if os.path.exists(f'{base_path}.{file_ext}') or os.path.exists(f'{base_path}/{self.filename}.{file_ext}'):
-                return False
+        ret_pdf = ret_cbz = None
+        if options.is_pdf:
+            ret_pdf = os.path.exists(f'{base_path}.pdf') or os.path.exists(f'{base_path}/{self.filename}.pdf')
+
+        if options.is_cbz:
+            ret_cbz = os.path.exists(f'{base_path}.cbz') or os.path.exists(f'{base_path}/{self.filename}.cbz')
+
+        if all(filter(lambda s: s is not None, [ret_cbz, ret_pdf])):
+            return False
 
         # doujinshi directory doesn't exist, re-download
         if not (os.path.exists(base_path) and os.path.isdir(base_path)):