diff --git a/gragir/prepare_epub.py b/gragir/prepare_epub.py
index 1003a5e..e751554 100644
--- a/gragir/prepare_epub.py
+++ b/gragir/prepare_epub.py
@@ -38,7 +38,8 @@ class PrepareEpub(object):
 
             cls._moveTo(item,local_url)
 
-            if mime == 'text/html':
+        for item in book.content.values():
+            if item.content_type == 'text/html':
                 cls._setXmlContent(item)