diff --git a/src/calibre/customize/builtins.py b/src/calibre/customize/builtins.py
index 68df832048..1ddb2843a1 100644
--- a/src/calibre/customize/builtins.py
+++ b/src/calibre/customize/builtins.py
@@ -226,8 +226,7 @@ class OPFMetadataReader(MetadataReaderPlugin):
 
     def get_metadata(self, stream, ftype):
         from calibre.ebooks.metadata.opf2 import OPF
-        from calibre.ebooks.metadata import MetaInformation
-        return MetaInformation(OPF(stream, os.getcwd()))
+        return OPF(stream, os.getcwd()).to_book_metadata()
 
 class PDBMetadataReader(MetadataReaderPlugin):
 
diff --git a/src/calibre/ebooks/conversion/plumber.py b/src/calibre/ebooks/conversion/plumber.py
index 16282dd28d..38e47f6bf7 100644
--- a/src/calibre/ebooks/conversion/plumber.py
+++ b/src/calibre/ebooks/conversion/plumber.py
@@ -692,7 +692,7 @@ OptionRecommendation(name='timestamp',
                                             self.opts.read_metadata_from_opf)
             opf = OPF(open(self.opts.read_metadata_from_opf, 'rb'),
                       os.path.dirname(self.opts.read_metadata_from_opf))
-            mi = MetaInformation(opf)
+            mi = opf.to_book_metadata()
         self.opts_to_mi(mi)
         if mi.cover:
             if mi.cover.startswith('http:') or mi.cover.startswith('https:'):
diff --git a/src/calibre/ebooks/metadata/cli.py b/src/calibre/ebooks/metadata/cli.py
index 780d3febcf..a0be187512 100644
--- a/src/calibre/ebooks/metadata/cli.py
+++ b/src/calibre/ebooks/metadata/cli.py
@@ -109,7 +109,7 @@ def do_set_metadata(opts, mi, stream, stream_type):
     from_opf = getattr(opts, 'from_opf', None)
     if from_opf is not None:
         from calibre.ebooks.metadata.opf2 import OPF
-        opf_mi = MetaInformation(OPF(open(from_opf, 'rb')))
+        opf_mi = OPF(open(from_opf, 'rb')).to_book_metadata()
         mi.smart_update(opf_mi)
 
     for pref in config().option_set.preferences:
diff --git a/src/calibre/ebooks/metadata/epub.py b/src/calibre/ebooks/metadata/epub.py
index ac6b5feebe..8984a252a3 100644
--- a/src/calibre/ebooks/metadata/epub.py
+++ b/src/calibre/ebooks/metadata/epub.py
@@ -167,7 +167,7 @@ def get_metadata(stream, extract_cover=True):
     """ Return metadata as a :class:`Metadata` object """
     stream.seek(0)
     reader = OCFZipReader(stream)
-    mi = MetaInformation(reader.opf)
+    mi = reader.opf.to_book_metadata()
     if extract_cover:
         try:
             cdata = get_cover(reader.opf, reader.opf_path, stream, reader=reader)
diff --git a/src/calibre/ebooks/metadata/lit.py b/src/calibre/ebooks/metadata/lit.py
index 1a267b6858..3be1f22632 100644
--- a/src/calibre/ebooks/metadata/lit.py
+++ b/src/calibre/ebooks/metadata/lit.py
@@ -6,7 +6,6 @@ Support for reading the metadata from a LIT file.
 
 import cStringIO, os
 
-from calibre.ebooks.metadata import MetaInformation
 from calibre.ebooks.metadata.opf2 import OPF
 
 def get_metadata(stream):
@@ -16,7 +15,7 @@ def get_metadata(stream):
     src = litfile.get_metadata().encode('utf-8')
     litfile = litfile._litfile
     opf = OPF(cStringIO.StringIO(src), os.getcwd())
-    mi = MetaInformation(opf)
+    mi = opf.to_book_metadata()
     covers = []
     for item in opf.iterguide():
         if 'cover' not in item.get('type', '').lower():
diff --git a/src/calibre/ebooks/metadata/meta.py b/src/calibre/ebooks/metadata/meta.py
index eae8171362..68deca5e10 100644
--- a/src/calibre/ebooks/metadata/meta.py
+++ b/src/calibre/ebooks/metadata/meta.py
@@ -194,7 +194,7 @@ def opf_metadata(opfpath):
     try:
         opf = OPF(f, os.path.dirname(opfpath))
         if opf.application_id is not None:
-            mi = MetaInformation(opf)
+            mi = opf.to_book_metadata()
             if hasattr(opf, 'cover') and opf.cover:
                 cpath = os.path.join(os.path.dirname(opfpath), opf.cover)
                 if os.access(cpath, os.R_OK):
diff --git a/src/calibre/ebooks/metadata/opf2.py b/src/calibre/ebooks/metadata/opf2.py
index 236b2fa18f..96f1fa4832 100644
--- a/src/calibre/ebooks/metadata/opf2.py
+++ b/src/calibre/ebooks/metadata/opf2.py
@@ -530,7 +530,7 @@ class OPF(object): # {{{
         self.read_user_metadata()
 
     def read_user_metadata(self):
-        self.user_metadata = {}
+        self._user_metadata_ = {}
         from calibre.utils.config import from_json
         elems = self.root.xpath('//*[name() = "meta" and starts-with(@name,'
                 '"calibre:user_metadata:") and @content]')
@@ -547,14 +547,21 @@ class OPF(object): # {{{
                 import traceback
                 traceback.print_exc()
                 continue
-            self.user_metadata[name] = fm
+            self._user_metadata_[name] = fm
 
+    def to_book_metadata(self):
+        ans = MetaInformation(self)
+        for n, v in self._user_metadata_.items():
+            ans.set_user_metadata(n, v)
+        return ans
 
     def write_user_metadata(self):
-        for elem in self.user_metadata_path(self.root):
+        elems = self.root.xpath('//*[name() = "meta" and starts-with(@name,'
+                '"calibre:user_metadata:") and @content]')
+        for elem in elems:
             elem.getparent().remove(elem)
         serialize_user_metadata(self.metadata,
-                self.user_metadata)
+                self._user_metadata_)
 
     def find_toc(self):
         self.toc = None
@@ -983,6 +990,9 @@ class OPF(object): # {{{
             val = getattr(mi, attr, None)
             if val is not None and val != [] and val != (None, None):
                 setattr(self, attr, val)
+        temp = self.to_book_metadata()
+        temp.smart_update(mi, replace_metadata=replace_metadata)
+        self._user_metadata_ = temp.get_all_user_metadata(True)
 
 # }}}
 
@@ -1417,9 +1427,9 @@ def test_user_metadata():
     opf = OPF(f)
     f2 = StringIO(raw2)
     opf2 = OPF(f2)
-    assert um == opf.user_metadata
-    assert um == opf2.user_metadata
-    print raw
+    assert um == opf._user_metadata_
+    assert um == opf2._user_metadata_
+    print opf.render()
 
 if __name__ == '__main__':
     test_user_metadata()
diff --git a/src/calibre/ebooks/mobi/reader.py b/src/calibre/ebooks/mobi/reader.py
index 2a35c7cb45..6a44c2aa77 100644
--- a/src/calibre/ebooks/mobi/reader.py
+++ b/src/calibre/ebooks/mobi/reader.py
@@ -441,7 +441,7 @@ class MobiReader(object):
                 html.tostring(elem, encoding='utf-8') + '</package>'
         stream = cStringIO.StringIO(raw)
         opf = OPF(stream)
-        self.embedded_mi = MetaInformation(opf)
+        self.embedded_mi = opf.to_book_metadata()
         if guide is not None:
             for ref in guide.xpath('descendant::reference'):
                 if 'cover' in ref.get('type', '').lower():
diff --git a/src/calibre/ebooks/oeb/reader.py b/src/calibre/ebooks/oeb/reader.py
index d7d7bbf725..559421326c 100644
--- a/src/calibre/ebooks/oeb/reader.py
+++ b/src/calibre/ebooks/oeb/reader.py
@@ -126,10 +126,9 @@ class OEBReader(object):
 
     def _metadata_from_opf(self, opf):
         from calibre.ebooks.metadata.opf2 import OPF
-        from calibre.ebooks.metadata import MetaInformation
         from calibre.ebooks.oeb.transforms.metadata import meta_info_to_oeb_metadata
         stream = cStringIO.StringIO(etree.tostring(opf))
-        mi = MetaInformation(OPF(stream))
+        mi = OPF(stream).to_book_metadata()
         if not mi.language:
             mi.language = get_lang().replace('_', '-')
         self.oeb.metadata.add('language', mi.language)
diff --git a/src/calibre/gui2/add.py b/src/calibre/gui2/add.py
index 5b9fb35be3..9f246aeb93 100644
--- a/src/calibre/gui2/add.py
+++ b/src/calibre/gui2/add.py
@@ -138,7 +138,7 @@ class DBAdder(Thread): # {{{
             self.critical[name] = open(opf, 'rb').read().decode('utf-8', 'replace')
         else:
             try:
-                mi = MetaInformation(OPF(opf))
+                mi = OPF(opf).to_book_metadata()
             except:
                 import traceback
                 mi = MetaInformation('', [_('Unknown')])
diff --git a/src/calibre/library/cli.py b/src/calibre/library/cli.py
index 9a2d0b0a62..cd4e472807 100644
--- a/src/calibre/library/cli.py
+++ b/src/calibre/library/cli.py
@@ -448,7 +448,7 @@ def command_show_metadata(args, dbpath):
     return 0
 
 def do_set_metadata(db, id, stream):
-    mi = OPF(stream)
+    mi = OPF(stream).to_book_metadata()
     db.set_metadata(id, mi)
     db.clean()
     do_show_metadata(db, id, False)