diff --git a/src/calibre/gui2/open_with.py b/src/calibre/gui2/open_with.py
index ee22819216..45d509e3dc 100644
--- a/src/calibre/gui2/open_with.py
+++ b/src/calibre/gui2/open_with.py
@@ -434,7 +434,8 @@ def register_keyboard_shortcuts(gui=None, finalize=False):
             name = _('Open {0} files with {1}').format(t, text)
             ac = QAction(gui)
             unique_name = application['uuid']
-            ac.triggered.connect(partial(gui.open_with_action_triggerred, filetype, application))
+            func = partial(gui.open_with_action_triggerred, filetype, application)
+            ac.triggered.connect(func)
             gui.keyboard.register_shortcut(unique_name, name, action=ac, group=_('Open With'))
             gui.addAction(ac)
             registered_shortcuts[unique_name] = ac
diff --git a/src/calibre/gui2/tweak_book/polish.py b/src/calibre/gui2/tweak_book/polish.py
index e3793457a6..83bc0af07e 100644
--- a/src/calibre/gui2/tweak_book/polish.py
+++ b/src/calibre/gui2/tweak_book/polish.py
@@ -91,10 +91,11 @@ def show_report(changed, title, report, parent, show_current_diff):
     d.l.addWidget(d.e)
     d.e.setHtml(report)
     d.bb = QDialogButtonBox(QDialogButtonBox.Close)
+    d.show_changes = False
     if changed:
         b = d.b = d.bb.addButton(_('See what &changed'), d.bb.AcceptRole)
         b.setIcon(QIcon(I('diff.png'))), b.setAutoDefault(False)
-        b.clicked.connect(lambda : show_current_diff(allow_revert=True), type=Qt.QueuedConnection)
+        connect_lambda(b.clicked, d, lambda d: setattr(d, 'show_changes', True))
     b = d.bb.addButton(_('&Copy to clipboard'), d.bb.ActionRole)
     b.setIcon(QIcon(I('edit-copy.png'))), b.setAutoDefault(False)
 
@@ -112,6 +113,8 @@ def show_report(changed, title, report, parent, show_current_diff):
     d.resize(600, 400)
     d.exec_()
     b.clicked.disconnect()
+    if d.show_changes:
+        show_current_diff(allow_revert=True)
 
 # CompressImages {{{