diff --git a/setup/qt-workarounds.txt b/setup/qt-workarounds.txt
deleted file mode 100644
index e2776fbcbc..0000000000
--- a/setup/qt-workarounds.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-Undo the workaround for WindowBlocked/Unblocked in Qt >= 5.6 
-https://bugreports.qt-project.org/browse/QTBUG-42281
-
diff --git a/src/calibre/gui2/dbus_export/widgets.py b/src/calibre/gui2/dbus_export/widgets.py
index 958cd9baf5..d3f0926379 100644
--- a/src/calibre/gui2/dbus_export/widgets.py
+++ b/src/calibre/gui2/dbus_export/widgets.py
@@ -31,6 +31,7 @@ class MenuBarAction(QAction):
     def menu(self):
         return self.parent()
 
+
 menu_counter = 0
 
 
@@ -58,10 +59,6 @@ class ExportedMenuBar(QMenuBar):  # {{{
         self.dbus_menu.publish_new_menu(self)
         self.register()
         parent.installEventFilter(self)
-        # See https://bugreports.qt-project.org/browse/QTBUG-42281
-        if hasattr(parent, 'window_blocked'):
-            parent.window_blocked.connect(self._block)
-            parent.window_unblocked.connect(self._unblock)
 
     def register(self, menu_registrar=None):
         self.menu_registrar = menu_registrar or self.menu_registrar
@@ -103,13 +100,6 @@ class ExportedMenuBar(QMenuBar):  # {{{
 
     def eventFilter(self, obj, ev):
         etype = ev.type()
-        # WindowBlocked and WindowUnblocked aren't delivered to event filters,
-        # so we have to rely on co-operation from the mainwindow class
-        # See https://bugreports.qt-project.org/browse/QTBUG-42281
-        # if etype == QEvent.WindowBlocked:
-        #     self._block()
-        # elif etype == QEvent.WindowUnblocked:
-        #     self._unblock()
         if etype == QEvent.Show:
             # Hiding a window causes the registrar to auto-unregister it, so we
             # have to re-register it on show events.
@@ -254,6 +244,7 @@ class Factory(QObject):
             self.bus
         # TODO: have the created widgets also handle bus disconnection
 
+
 _factory = None
 
 
diff --git a/src/calibre/gui2/main_window.py b/src/calibre/gui2/main_window.py
index 7f5d94de94..fd71725f44 100644
--- a/src/calibre/gui2/main_window.py
+++ b/src/calibre/gui2/main_window.py
@@ -8,7 +8,7 @@ __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 import StringIO, traceback, sys, gc, weakref
 
 from PyQt5.Qt import (QMainWindow, QTimer, QAction, QMenu, QMenuBar, QIcon,
-                      pyqtSignal, QObject)
+                      QObject)
 from calibre.utils.config import OptionParser
 from calibre.gui2 import error_dialog
 from calibre import prints
@@ -90,10 +90,6 @@ class MainWindow(QMainWindow):
     ___menu     = None
     __actions   = []
 
-    # See https://bugreports.qt-project.org/browse/QTBUG-42281
-    window_blocked = pyqtSignal()
-    window_unblocked = pyqtSignal()
-
     @classmethod
     def create_application_menubar(cls):
         if not cls.__actions:
@@ -156,15 +152,6 @@ class MainWindow(QMainWindow):
         except:
             pass
 
-    def event(self, ev):
-        # See https://bugreports.qt-project.org/browse/QTBUG-42281
-        etype = ev.type()
-        if etype == ev.WindowBlocked:
-            self.window_blocked.emit()
-        elif etype == ev.WindowUnblocked:
-            self.window_unblocked.emit()
-        return QMainWindow.event(self, ev)
-
 
 def clone_menu(menu):
     # This is needed to workaround a bug in Qt 5.5+ and Unity. When the same