diff --git a/src/pyj/srv.pyj b/src/pyj/srv.pyj
index a77be229e1..61687d8520 100644
--- a/src/pyj/srv.pyj
+++ b/src/pyj/srv.pyj
@@ -13,6 +13,8 @@ def on_library_loaded(end_type, xhr, ev):
     p.parentNode.removeChild(p)
     if end_type == 'load':
         interface_data = JSON.parse(xhr.responseText)
+        # TODO: Copy any user specific session data from the server to
+        # the local session data object, overriding local data
         boss = Boss(interface_data)
         set_boss(boss)
     else:
@@ -27,8 +29,11 @@ def on_library_load_progress(loaded, total):
 
 def load_book_list():
     sd = set_session_data(UserSessionData(window.calibre_username))
-    ajax('ajax/interface-data', on_library_loaded, on_library_load_progress, query={
-        'library_id':sd.get('library_id'), 'sort':sd.get('sort')}).send()
+    query = {}
+    if not sd.has_user:
+        # For authenticated users use the session data cached on the server
+        query = {'library_id':sd.get('library_id'), 'sort':sd.get('sort')}
+    ajax('ajax/interface-data', on_library_loaded, on_library_load_progress, query=query).send()
 
 def on_load():
     if window.calibre_entry_point == 'book list':