diff --git a/src/calibre/ebooks/oeb/transforms/flatcss.py b/src/calibre/ebooks/oeb/transforms/flatcss.py
index 9a5ff36d55..7212bd33c6 100644
--- a/src/calibre/ebooks/oeb/transforms/flatcss.py
+++ b/src/calibre/ebooks/oeb/transforms/flatcss.py
@@ -289,7 +289,7 @@ class CSSFlattener(object):
 
         if (self.context.remove_paragraph_spacing or
                 self.context.insert_blank_line) and tag in ('p', 'div'):
-            if item_id != 'jacket' or self.context.output_profile.name == 'Kindle':
+            if item_id != 'calibre_jacket' or self.context.output_profile.name == 'Kindle':
                 for prop in ('margin', 'padding', 'border'):
                     for edge in ('top', 'bottom'):
                         cssdict['%s-%s'%(prop, edge)] = '0pt'
diff --git a/src/calibre/ebooks/oeb/transforms/jacket.py b/src/calibre/ebooks/oeb/transforms/jacket.py
index 309a7fd7b6..6786d7cf9c 100644
--- a/src/calibre/ebooks/oeb/transforms/jacket.py
+++ b/src/calibre/ebooks/oeb/transforms/jacket.py
@@ -181,7 +181,7 @@ class Jacket(object):
 
             return soup.renderContents()
 
-        id, href = self.oeb.manifest.generate('jacket', 'jacket.xhtml')
+        id, href = self.oeb.manifest.generate('calibre_jacket', 'jacket.xhtml')
         from calibre.ebooks.oeb.base import RECOVER_PARSER, XPath
 
         try: