diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index 83851b60c6..3c9066b5fb 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -21,6 +21,7 @@ from calibre import as_unicode, prints
 from calibre.constants import (
     FAKE_HOST, FAKE_PROTOCOL, __version__, is_running_from_develop
 )
+from calibre.ebooks.metadata.book.base import field_metadata
 from calibre.ebooks.oeb.polish.utils import guess_type
 from calibre.gui2 import error_dialog, open_url
 from calibre.gui2.webengine import (
@@ -389,7 +390,7 @@ class WebView(RestartingWebEngineView):
         return self._page.bridge
 
     def on_bridge_ready(self):
-        self.bridge.create_view(vprefs['session_data'], QFontDatabase().families())
+        self.bridge.create_view(vprefs['session_data'], QFontDatabase().families(), field_metadata.all_metadata())
         for func, args in iteritems(self.pending_bridge_ready_actions):
             getattr(self.bridge, func)(*args)
 
diff --git a/src/pyj/book_list/book_details.pyj b/src/pyj/book_list/book_details.pyj
index 7ac3acc62c..0c690c7015 100644
--- a/src/pyj/book_list/book_details.pyj
+++ b/src/pyj/book_list/book_details.pyj
@@ -248,7 +248,10 @@ def render_metadata(mi, table, book_id):  # {{{
             table.appendChild(E.tr(E.td(name + ':'), E.td()))
             td = table.lastChild.lastChild
             for k in val:
-                lang = mi.lang_names[k] or k
+                if mi.lang_names:
+                    lang = mi.lang_names[k] or k
+                else:
+                    lang = k
                 td.appendChild(E.a(lang,
                     title=_('Click to see books with language: {}').format(lang),
                     href=href_for_search(field, k)
diff --git a/src/pyj/viewer-main.pyj b/src/pyj/viewer-main.pyj
index 846720ebae..8b9a1a876b 100644
--- a/src/pyj/viewer-main.pyj
+++ b/src/pyj/viewer-main.pyj
@@ -10,6 +10,7 @@ import initialize  # noqa: unused-import
 from ajax import ajax
 from book_list.globals import set_session_data
 from book_list.theme import get_color, get_font_family
+from book_list.library_data import library_data
 from dom import get_widget_css, set_css
 from modals import create_modal_container, error_dialog
 from qt import from_python, to_python
@@ -176,9 +177,10 @@ def create_session_data(prefs):
 
 
 @from_python
-def create_view(prefs, all_font_families):
+def create_view(prefs, all_font_families, field_metadata):
     nonlocal view
     runtime.all_font_families = all_font_families
+    library_data.field_metadata = field_metadata
     if view is None:
         create_session_data(prefs)
         view = View(document.getElementById('view'))