diff --git a/src/calibre/ebooks/metadata/epub.py b/src/calibre/ebooks/metadata/epub.py
index 5b8f75c3b1..bc81df5a79 100644
--- a/src/calibre/ebooks/metadata/epub.py
+++ b/src/calibre/ebooks/metadata/epub.py
@@ -289,9 +289,8 @@ def set_metadata(stream, mi, apply_null=False, update_timestamp=False):
             langs.append(lc)
         mi.languages = langs
 
-    reader.opf.smart_update(mi)
-    reader.opf.add_uuid_identifier(mi.uuid)
 
+    reader.opf.smart_update(mi)
     if apply_null:
         if not getattr(mi, 'series', None):
             reader.opf.series = None
diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 5d853288de..3e5d95f1ce 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -1163,9 +1163,6 @@ class OPF(object): # {{{
         temp.smart_update(mi, replace_metadata=replace_metadata)
         self._user_metadata_ = temp.get_all_user_metadata(True)
 
-    def add_uuid_identifier(self,uuid):
-        setattr(self,'uuid',uuid)
-
 # }}}
 
 class OPFCreator(Metadata):