diff --git a/cbz2ebook.py b/cbz2ebook.py
index e269428..554d3ec 100755
--- a/cbz2ebook.py
+++ b/cbz2ebook.py
@@ -70,7 +70,7 @@ else:
 
 for idx, im in enumerate(
     tqdm(
-        mapper(process_image, map(Image.open, map(srczip.open, srcfiles)),),
+        mapper(process_image, mapper(Image.open, mapper(srczip.open, srcfiles)),),
         total=len(srcfiles),
     )
 ):