diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 329df37617..0f744e3708 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1289,15 +1289,3 @@ def event_type_name(ev_or_etype):
         if num == etype:
             return name
     return 'UnknownEventType'
-
-if islinux or isbsd:
-    def workaround_broken_under_mouse(ch):
-        import sip
-        from PyQt5.Qt import QCursor, QToolButton
-        # See https://bugreports.qt-project.org/browse/QTBUG-40233
-        if isinstance(ch, QToolButton) and not sip.isdeleted(ch):
-            ch.setAttribute(Qt.WA_UnderMouse, ch.rect().contains(ch.mapFromGlobal(QCursor.pos())))
-            ch.update()
-else:
-    workaround_broken_under_mouse = None
-
diff --git a/src/calibre/gui2/bars.py b/src/calibre/gui2/bars.py
index ea854a54a6..6b0c13e54e 100644
--- a/src/calibre/gui2/bars.py
+++ b/src/calibre/gui2/bars.py
@@ -7,15 +7,13 @@ __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-from functools import partial
-
 import sip
 from PyQt5.Qt import (
     Qt, QAction, QMenu, QObject, QToolBar, QToolButton, QSize, pyqtSignal, QTimer)
 
 from calibre.constants import isosx
 from calibre.gui2.throbber import create_donate_widget
-from calibre.gui2 import gprefs, workaround_broken_under_mouse, native_menubar_defaults
+from calibre.gui2 import gprefs, native_menubar_defaults
 
 class ToolBar(QToolBar):  # {{{
 
@@ -110,8 +108,6 @@ class ToolBar(QToolBar):  # {{{
         ch.setAutoRaise(True)
         m = ac.menu()
         if m is not None:
-            if workaround_broken_under_mouse is not None:
-                m.aboutToHide.connect(partial(workaround_broken_under_mouse, ch))
             if menu_mode is not None:
                 ch.setPopupMode(menu_mode)
         return ch
diff --git a/src/calibre/gui2/tweak_book/editor/widget.py b/src/calibre/gui2/tweak_book/editor/widget.py
index b8588a19bd..ac22e2c601 100644
--- a/src/calibre/gui2/tweak_book/editor/widget.py
+++ b/src/calibre/gui2/tweak_book/editor/widget.py
@@ -19,7 +19,7 @@ from calibre.ebooks.chardet import replace_encoding_declarations
 from calibre.gui2.tweak_book import (
     actions, current_container, tprefs, dictionaries, editor_toolbar_actions,
     editor_name, editors, update_mark_text_action)
-from calibre.gui2 import error_dialog, open_url, workaround_broken_under_mouse
+from calibre.gui2 import error_dialog, open_url
 from calibre.gui2.tweak_book.editor import SPELL_PROPERTY, LINK_PROPERTY, TAG_NAME_PROPERTY, CSS_PROPERTY
 from calibre.gui2.tweak_book.editor.help import help_url
 from calibre.gui2.tweak_book.editor.text import TextEdit
@@ -340,19 +340,11 @@ class Editor(QMainWindow):
                 w.setContextMenuPolicy(Qt.CustomContextMenu)
                 w.customContextMenuRequested.connect(w.showMenu)
                 self._build_insert_tag_button_menu()
-                if workaround_broken_under_mouse is not None:
-                    try:
-                        self.insert_tag_menu.aboutToHide.disconnect()
-                    except TypeError:
-                        pass
-                    self.insert_tag_menu.aboutToHide.connect(partial(workaround_broken_under_mouse, w))
             elif name == 'change-paragraph':
                 m = ac.m = QMenu()
                 ac.setMenu(m)
                 ch = bar.widgetForAction(ac)
                 ch.setPopupMode(QToolButton.InstantPopup)
-                if workaround_broken_under_mouse is not None:
-                    m.aboutToHide.connect(partial(workaround_broken_under_mouse, ch))
                 for name in tuple('h%d' % d for d in range(1, 7)) + ('p',):
                     m.addAction(actions['rename-block-tag-%s' % name])
 
diff --git a/src/calibre/gui2/viewer/ui.py b/src/calibre/gui2/viewer/ui.py
index 638d00264f..f38ae6c3be 100644
--- a/src/calibre/gui2/viewer/ui.py
+++ b/src/calibre/gui2/viewer/ui.py
@@ -7,7 +7,6 @@ __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
 import textwrap
-from functools import partial
 
 from PyQt5.Qt import (
     QIcon, QWidget, Qt, QGridLayout, QScrollBar, QToolBar, QAction,
@@ -15,7 +14,7 @@ from PyQt5.Qt import (
     QRegExpValidator, QRegExp, QPalette, QColor, QBrush, QPainter,
     QDockWidget, QSize, QWebView, QLabel, QVBoxLayout)
 
-from calibre.gui2 import rating_font, workaround_broken_under_mouse
+from calibre.gui2 import rating_font
 from calibre.gui2.main_window import MainWindow
 from calibre.gui2.search_box import SearchBox2
 from calibre.gui2.viewer.documentview import DocumentView
@@ -336,13 +335,6 @@ class Main(MainWindow):
 
         self.resize(653, 746)
 
-        if workaround_broken_under_mouse is not None:
-            for bar in (self.tool_bar, self.tool_bar2):
-                for ac in bar.actions():
-                    m = ac.menu()
-                    if m is not None:
-                        m.aboutToHide.connect(partial(workaround_broken_under_mouse, bar.widgetForAction(ac)))
-
     def resizeEvent(self, ev):
         if self.metadata.isVisible():
             self.metadata.update_layout()