diff --git a/nhentai/command.py b/nhentai/command.py
index 47fbc3c..d0fce3d 100644
--- a/nhentai/command.py
+++ b/nhentai/command.py
@@ -94,8 +94,11 @@ def main():
             elif options.is_pdf:
                 generate_pdf(options.output_dir, doujinshi, options.rm_origin_dir)
 
-        if options.main_viewer:
+        if options.main_viewer and options.output_dir:
             generate_main_html(options.output_dir)
+        elif options.main_viewer:
+            generate_main_html()
+
 
         if not platform.system() == 'Windows':
             logger.log(15, '🍻 All done.')