diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index a83ae48d94..88ea9b7f69 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -159,6 +159,8 @@ View an e-book.
     a('--full-screen', '--fullscreen', '-f', default=False, action='store_true',
         help=_('If specified, viewer window will try to open '
                'full screen when started.'))
+    a('--force-reload', default=False, action='store_true',
+        help=_('Force reload of all opened books'))
     a('--open-at', default=None, help=_(
         'The position at which to open the specified book. The position is '
         'a location you can get by using the Goto action in the viewer controls. '
@@ -203,7 +205,7 @@ def main(args=sys.argv):
     app.load_builtin_fonts()
     app.setWindowIcon(QIcon(I('viewer.png')))
     migrate_previous_viewer_prefs()
-    main = EbookViewer(open_at=opts.open_at, continue_reading=opts.continue_reading)
+    main = EbookViewer(open_at=opts.open_at, continue_reading=opts.continue_reading, force_reload=opts.force_reload)
     main.set_exception_handler()
     if len(args) > 1:
         acc.events.append(os.path.abspath(args[-1]))
diff --git a/src/calibre/gui2/viewer/ui.py b/src/calibre/gui2/viewer/ui.py
index 356649bae0..2a181b09d8 100644
--- a/src/calibre/gui2/viewer/ui.py
+++ b/src/calibre/gui2/viewer/ui.py
@@ -77,8 +77,9 @@ class EbookViewer(MainWindow):
     book_prepared = pyqtSignal(object, object)
     MAIN_WINDOW_STATE_VERSION = 1
 
-    def __init__(self, open_at=None, continue_reading=None):
+    def __init__(self, open_at=None, continue_reading=None, force_reload=False):
         MainWindow.__init__(self, None)
+        self.force_reload = force_reload
         connect_lambda(self.book_preparation_started, self, lambda self: self.loading_overlay(_(
             'Preparing book for first read, please wait')), type=Qt.QueuedConnection)
         self.maximized_at_last_fullscreen = False
@@ -302,7 +303,7 @@ class EbookViewer(MainWindow):
         self.loading_overlay(_('Loading book, please wait'))
         self.save_annotations()
         self.current_book_data = {}
-        t = Thread(name='LoadBook', target=self._load_ebook_worker, args=(pathtoebook, open_at, reload_book))
+        t = Thread(name='LoadBook', target=self._load_ebook_worker, args=(pathtoebook, open_at, reload_book or self.force_reload))
         t.daemon = True
         t.start()