diff --git a/src/calibre/gui2/ui.py b/src/calibre/gui2/ui.py
index 86aaa7c89c..88c8f3ccca 100644
--- a/src/calibre/gui2/ui.py
+++ b/src/calibre/gui2/ui.py
@@ -982,6 +982,7 @@ class Main(MainWindow, Ui_MainWindow, DeviceGUI):
 
             update_progress = pyqtSignal(int)
             update_done     = pyqtSignal()
+            FINISHED_READING_PCT_THRESHOLD = 96
 
             def __init__(self, parent, db, annotation_map, done_callback):
                 QThread.__init__(self, parent)
@@ -1064,6 +1065,10 @@ class Main(MainWindow, Ui_MainWindow, DeviceGUI):
                 ka_soup.insert(0,divTag)
                 return ka_soup
 
+            def mark_book_as_read(self,id):
+                read_tag = gprefs.get('catalog_epub_mobi_read_tag')
+                self.db.set_tags(id, [read_tag], append=True)
+
             def canceled(self):
                 self.pd.hide()
 
@@ -1091,6 +1096,9 @@ class Main(MainWindow, Ui_MainWindow, DeviceGUI):
                         mi.comments = unicode(user_notes_soup.prettify())
                     # Update library comments
                     self.db.set_comment(id, mi.comments)
+                    # Update 'read' tag
+                    if bm.bookmark.percent_read >= self.FINISHED_READING_PCT_THRESHOLD:
+                        self.mark_book_as_read(id)
                     # Add bookmark file to id
                     self.db.add_format_with_hooks(id, bm.bookmark.bookmark_extension,
                                                   bm.bookmark.path, index_is_id=True)
diff --git a/src/calibre/ptempfile.py b/src/calibre/ptempfile.py
index b71ff15f65..b7b4d49509 100644
--- a/src/calibre/ptempfile.py
+++ b/src/calibre/ptempfile.py
@@ -51,32 +51,6 @@ class PersistentTemporaryFile(object):
         except:
             pass
 
-    def startswith(self,*args):
-        if len(args):
-            str = args[0]
-            beg = 0
-            end = len(str)
-        else:
-            return False
-
-        if len(args) > 1:
-            begin = args[1]
-        if len(args) > 2:
-            end = args[2]
-        if self._name[beg:end].startswith(str):
-            return True
-        return False
-
-    def split(self,*args):
-        if len(args):
-            sep = args[0]
-        if len(args) > 1:
-            maxsplit = args[1]
-            return self._name.split(sep,maxsplit)
-        else:
-            return self._name.split(sep)
-
-
 def PersistentTemporaryDirectory(suffix='', prefix='', dir=None):
     '''
     Return the path to a newly created temporary directory that will