diff --git a/pdf2book.py b/pdf2book.py
index 9878f56..39652c9 100755
--- a/pdf2book.py
+++ b/pdf2book.py
@@ -202,6 +202,9 @@ def make_zine(reader, lst):
 lst=get_reorder(number_of_pages, signature_size)
 if args.zine :
     if number_of_pages != 16:
+        #TODO: if number of pages%16 != 0 : fill up with blank pages
+        # in loop: 
+        #   if i > len(pages): insert blank? or terminate orderly
         print("Error... when using '--zine' the input pdf must have 16 pages!")
         exit(1)
     writer=make_zine(reader, lst)