diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 27d748cc31..9a3868b428 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -1163,7 +1163,7 @@ class OPF(object):  # {{{
             for item in self.itermanifest():
                 if item.get('href', None) == cover_id:
                     mt = item.get('media-type', '')
-                    if mt and mt.startswith('image/'):
+                    if mt and 'xml' not in mt and 'html' not in mt:
                         return item.get('href', None)
         elif self.package_version >= 3.0:
             for item in self.itermanifest():