diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 64dddd2f8..580e532f8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -56,7 +56,8 @@ jobs:
       - name: Install dependencies
         run: |
             [[ ${{ matrix.testenv }} == eslint ]] && npm install -g eslint
-            [[ ${{ matrix.testenv }} == docs ]] && sudo apt-get update && sudo apt-get install --no-install-recommends asciidoc
+            [[ ${{ matrix.testenv }} == docs ]] && sudo apt-get update && sudo apt-get install --no-install-recommends asciidoc libegl1-mesa
+            [[ ${{ matrix.testenv }} == vulture || ${{ matrix.testenv }} == pylint ]] && sudo apt-get update && sudo apt-get install --no-install-recommends libegl1-mesa
             if [[ ${{ matrix.testenv }} == shellcheck ]]; then
                 scversion="stable"
                 bindir="$HOME/.local/bin"
@@ -89,17 +90,16 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - testenv: py
+          - testenv: py-qt5
             image: archlinux-webkit
-          - testenv: py
+          - testenv: py-qt5
             image: archlinux-webengine
-          - testenv: py-qt6
+          - testenv: py-qt5
+            image: archlinux-webengine-unstable
+          - testenv: py
             image: archlinux-webengine-qt6
           - testenv: py
-            image: archlinux-webengine-unstable
-            args: ""
-            # - testenv: py
-            #   image: archlinux-webengine-unstable-qt6  # FIXME:qt6.5 activate
+            image: archlinux-webengine-unstable-qt6
     container:
       image: "qutebrowser/ci:${{ matrix.image }}"
       env:
@@ -115,9 +115,9 @@ jobs:
         with:
           persist-credentials: false
       - name: Set up problem matchers
-        run: "python scripts/dev/ci/problemmatchers.py py38 ${{ runner.temp }}"
+        run: "python scripts/dev/ci/problemmatchers.py tests ${{ runner.temp }}"
       - name: Run tox
-        run: "dbus-run-session -- tox -e ${{ matrix.testenv }} -- ${{ matrix.args }}"
+        run: "dbus-run-session -- tox -e ${{ matrix.testenv }}"
 
   tests:
     if: "!contains(github.event.head_commit.message, '[ci skip]')"
diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index cabf2d8c4..68d2243a4 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -15,6 +15,7 @@ jobs:
           - archlinux-webkit
           - archlinux-webengine
           - archlinux-webengine-unstable
+          - archlinux-webengine-unstable-qt6
           - archlinux-webengine-qt6
     steps:
       - uses: actions/checkout@v3
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 2254abb4a..c1a8dda8a 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -16,50 +16,50 @@ jobs:
         include:
           - os: macos-11
             branch: master
+            toxenv: build-release-qt5
+            name: qt5-macos
+          - os: windows-2019
+            args: --64bit
+            branch: master
+            toxenv: build-release-qt5
+            name: qt5-windows-64bit
+          - os: windows-2019
+            args: --32bit
+            branch: master
+            toxenv: build-release-qt5
+            name: qt5-windows-32bit
+
+          - os: macos-11
+            args: --debug
+            branch: master
+            toxenv: build-release-qt5
+            name: qt5-macos-debug
+          - os: windows-2019
+            args: --64bit --debug
+            branch: master
+            toxenv: build-release-qt5
+            name: qt5-windows-64bit-debug
+          - os: windows-2019
+            args: --32bit --debug
+            branch: master
+            toxenv: build-release-qt5
+            name: qt5-windows-32bit-debug
+
+          - os: macos-11
             toxenv: build-release
             name: macos
           - os: windows-2019
             args: --64bit
-            branch: master
             toxenv: build-release
             name: windows-64bit
-          - os: windows-2019
-            args: --32bit
-            branch: master
-            toxenv: build-release
-            name: windows-32bit
-
           - os: macos-11
             args: --debug
-            branch: master
             toxenv: build-release
             name: macos-debug
           - os: windows-2019
             args: --64bit --debug
-            branch: master
             toxenv: build-release
             name: windows-64bit-debug
-          - os: windows-2019
-            args: --32bit --debug
-            branch: master
-            toxenv: build-release
-            name: windows-32bit-debug
-
-          - os: macos-11
-            toxenv: build-release-qt6
-            name: qt6-macos
-          - os: windows-2019
-            args: --64bit
-            toxenv: build-release-qt6
-            name: qt6-windows-64bit
-          - os: macos-11
-            args: --debug
-            toxenv: build-release-qt6
-            name: qt6-macos-debug
-          - os: windows-2019
-            args: --64bit --debug
-            toxenv: build-release-qt6
-            name: qt6-windows-64bit-debug
     runs-on: "${{ matrix.os }}"
     timeout-minutes: 45
     steps:
diff --git a/.pylintrc b/.pylintrc
index f89e3fa50..341bbe8cb 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -1,6 +1,6 @@
 [MASTER]
 ignore=resources.py
-extension-pkg-whitelist=PyQt5,sip
+extension-pkg-whitelist=PyQt5,PyQt6,sip
 load-plugins=qute_pylint.config,
              pylint.extensions.docstyle,
              pylint.extensions.emptystring,
@@ -58,8 +58,8 @@ disable=locally-disabled,
         missing-type-doc,
         missing-param-doc,
         useless-param-doc,
-        wrong-import-order,  # FIXME:qt6 (lint)
-        ungrouped-imports,  # FIXME:qt6 (lint)
+        wrong-import-order,  # doesn't work with qutebrowser.qt, even with known-third-party set
+        ungrouped-imports,   # ditto
 
 [BASIC]
 function-rgx=[a-z_][a-z0-9_]{2,50}$
diff --git a/doc/changelog.asciidoc b/doc/changelog.asciidoc
index 666e24177..b8bce1545 100644
--- a/doc/changelog.asciidoc
+++ b/doc/changelog.asciidoc
@@ -19,6 +19,17 @@ breaking changes (such as renamed commands) can happen in minor releases.
 v3.0.0 (unreleased)
 -------------------
 
+Major changes
+~~~~~~~~~~~~~
+
+- qutebrowser now supports Qt 6 and uses it by default. Qt 5.15 is used as a
+  fallback if Qt 6 is unavailable. This behavior can be customized in three ways
+  (in order of precedence):
+  * Via `--qt-wrapper PyQt5` or `--qt-wrapper PyQt6` command-line arguments.
+  * Via the `QUTE_QT_WRAPPER` environment variable, set to `PyQt6` or `PyQt5`.
+  * For packagers wanting to provide packages specific to a Qt version,
+    patch `qutebrowser/qt/machinery.py` and set `_WRAPPER_OVERRIDE`.
+
 Added
 ~~~~~
 
diff --git a/misc/qutebrowser.spec b/misc/qutebrowser.spec
index 467994bab..1eee9161d 100644
--- a/misc/qutebrowser.spec
+++ b/misc/qutebrowser.spec
@@ -82,7 +82,7 @@ def get_data_files():
 
 
 def get_hidden_imports():
-    imports = [] if "PYINSTALLER_QT6" in os.environ else ['PyQt5.QtOpenGL']
+    imports = ["PyQt5.QtOpenGL"] if "PYINSTALLER_QT5" in os.environ else []
     for info in loader.walk_components():
         imports.append(info.name)
     return imports
diff --git a/misc/requirements/requirements-pyqt.txt b/misc/requirements/requirements-pyqt.txt
index 029fb4a6b..26f81ab23 100644
--- a/misc/requirements/requirements-pyqt.txt
+++ b/misc/requirements/requirements-pyqt.txt
@@ -1,7 +1,7 @@
 # This file is automatically generated by scripts/dev/recompile_requirements.py
 
-PyQt5==5.15.9
-PyQt5-Qt5==5.15.2
-PyQt5-sip==12.12.1
-PyQtWebEngine==5.15.6
-PyQtWebEngine-Qt5==5.15.2
+PyQt6==6.5.1
+PyQt6-Qt6==6.5.1
+PyQt6-sip==13.5.1
+PyQt6-WebEngine==6.5.0
+PyQt6-WebEngine-Qt6==6.5.1
diff --git a/misc/requirements/requirements-pyqt.txt-raw b/misc/requirements/requirements-pyqt.txt-raw
index 9c6afbf16..68a5db685 100644
--- a/misc/requirements/requirements-pyqt.txt-raw
+++ b/misc/requirements/requirements-pyqt.txt-raw
@@ -1,2 +1,4 @@
-PyQt5
-PyQtWebEngine
+PyQt6
+PyQt6-Qt6
+PyQt6-WebEngine
+PyQt6-WebEngine-Qt6
diff --git a/misc/userscripts/add-nextcloud-bookmarks b/misc/userscripts/add-nextcloud-bookmarks
index 86f4f5bc7..2a480ccff 100755
--- a/misc/userscripts/add-nextcloud-bookmarks
+++ b/misc/userscripts/add-nextcloud-bookmarks
@@ -41,7 +41,7 @@ from json import dumps
 from os import environ, path
 from sys import argv, exit
 
-from PyQt5.QtWidgets import QApplication, QInputDialog, QLineEdit
+from PyQt6.QtWidgets import QApplication, QInputDialog, QLineEdit
 from requests import get, post
 from requests.auth import HTTPBasicAuth
 
@@ -54,7 +54,7 @@ def get_text(name, info):
             None,
             "add-nextcloud-bookmarks userscript",
             "Please enter {}".format(info),
-            QLineEdit.Password,
+            QLineEdit.EchoMode.Password,
         )
     else:
         text, ok = QInputDialog.getText(
diff --git a/misc/userscripts/add-nextcloud-cookbook b/misc/userscripts/add-nextcloud-cookbook
index 3952bb16f..151090785 100755
--- a/misc/userscripts/add-nextcloud-cookbook
+++ b/misc/userscripts/add-nextcloud-cookbook
@@ -37,7 +37,7 @@ import configparser
 from os import environ, path
 from sys import argv, exit
 
-from PyQt5.QtWidgets import QApplication, QInputDialog, QLineEdit
+from PyQt6.QtWidgets import QApplication, QInputDialog, QLineEdit
 from requests import post
 from requests.auth import HTTPBasicAuth
 
@@ -50,7 +50,7 @@ def get_text(name, info):
             None,
             "add-nextcloud-cookbook userscript",
             "Please enter {}".format(info),
-            QLineEdit.Password,
+            QLineEdit.EchoMode.Password,
         )
     else:
         text, ok = QInputDialog.getText(
diff --git a/misc/userscripts/qute-keepass b/misc/userscripts/qute-keepass
index 285377ffc..f88493d8e 100755
--- a/misc/userscripts/qute-keepass
+++ b/misc/userscripts/qute-keepass
@@ -42,7 +42,7 @@ you do not do this, you will get 'element not editable' errors.
 If keepass takes a while to open the DB, you might want to consider reducing
 the number of transform rounds in your database settings.
 
-Dependencies: pykeepass (in python3), PyQt5. Without pykeepass, you will get an
+Dependencies: pykeepass (in python3), PyQt6. Without pykeepass, you will get an
 exit code of 100.
 
 ********************!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!******************
@@ -64,8 +64,8 @@ import shlex
 import subprocess
 import sys
 
-from PyQt5.QtCore import QUrl
-from PyQt5.QtWidgets import QApplication, QInputDialog, QLineEdit
+from PyQt6.QtCore import QUrl
+from PyQt6.QtWidgets import QApplication, QInputDialog, QLineEdit
 
 try:
     import pykeepass
@@ -152,7 +152,7 @@ def get_password():
     text, ok = QInputDialog.getText(
         None, "KeePass DB Password",
         "Please enter your KeePass Master Password",
-        QLineEdit.Password)
+        QLineEdit.EchoMode.Password)
     if not ok:
         stderr('Password Prompt Rejected.')
         sys.exit(ExitCodes.USER_QUIT)
diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index bb2ff56e7..fbfa3df12 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -367,6 +367,14 @@ def _open_special_pages(args):
              os.environ.get("QTWEBENGINE_DISABLE_SANDBOX") == "1"
          ),
          'qute://warning/sandboxing'),
+
+        ('qt5-warning-shown',
+         (
+             machinery.IS_QT5 and
+             machinery.INFO.reason == machinery.SelectionReason.auto and
+             objects.backend != usertypes.Backend.QtWebKit,
+         ),
+         'qute://warning/qt5'),
     ]
 
     if 'quickstart-done' not in general_sect:
diff --git a/qutebrowser/browser/qutescheme.py b/qutebrowser/browser/qutescheme.py
index 25834670b..0073f9bd2 100644
--- a/qutebrowser/browser/qutescheme.py
+++ b/qutebrowser/browser/qutescheme.py
@@ -22,6 +22,7 @@ Module attributes:
     _HANDLERS: The handlers registered via decorators.
 """
 
+import sys
 import html
 import json
 import os
@@ -583,6 +584,12 @@ def qute_warning(url: QUrl) -> _HandlerRet:
     elif path == '/sandboxing':
         src = jinja.render('warning-sandboxing.html',
                            title='Qt 6 macOS sandboxing warning')
+    elif path == '/qt5':
+        is_venv = hasattr(sys, 'real_prefix') or sys.base_prefix != sys.prefix
+        src = jinja.render('warning-qt5.html',
+                           title='Switch to Qt 6',
+                           is_venv=is_venv,
+                           prefix=sys.prefix)
     else:
         raise NotFoundError("Invalid warning page {}".format(path))
     return 'text/html', src
diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index e55d75ecd..c2957181b 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -400,7 +400,8 @@ class WebEngineCaret(browsertab.AbstractCaret):
         # https://bugreports.qt.io/browse/QTBUG-53134
         # Even on Qt 5.10 selectedText() seems to work poorly, see
         # https://github.com/qutebrowser/qutebrowser/issues/3523
-        # FIXME:qt6 Reevaluate?
+        # With Qt 6.2-6.5, there still seem to be issues (especially with
+        # multi-line text)
         self._tab.run_js_async(javascript.assemble('caret', 'getSelection'),
                                callback)
 
diff --git a/qutebrowser/browser/webkit/webkitelem.py b/qutebrowser/browser/webkit/webkitelem.py
index ef3e3bea5..8bf5031b1 100644
--- a/qutebrowser/browser/webkit/webkitelem.py
+++ b/qutebrowser/browser/webkit/webkitelem.py
@@ -15,16 +15,15 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """QtWebKit specific part of the web element API."""
 
 from typing import cast, TYPE_CHECKING, Iterator, List, Optional, Set
 
 from qutebrowser.qt.core import QRect, Qt
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebElement, QWebSettings
 from qutebrowser.qt.webkitwidgets import QWebFrame
+# pylint: enable=no-name-in-module
 
 from qutebrowser.config import config
 from qutebrowser.utils import log, utils, javascript, usertypes
diff --git a/qutebrowser/browser/webkit/webkithistory.py b/qutebrowser/browser/webkit/webkithistory.py
index aea648361..d89c705e6 100644
--- a/qutebrowser/browser/webkit/webkithistory.py
+++ b/qutebrowser/browser/webkit/webkithistory.py
@@ -15,14 +15,13 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """QtWebKit specific part of history."""
 
 import functools
 
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebHistoryInterface
+# pylint: enable=no-name-in-module
 
 from qutebrowser.utils import debug
 from qutebrowser.misc import debugcachestats
diff --git a/qutebrowser/browser/webkit/webkitinspector.py b/qutebrowser/browser/webkit/webkitinspector.py
index cb9cb5615..c181435d1 100644
--- a/qutebrowser/browser/webkit/webkitinspector.py
+++ b/qutebrowser/browser/webkit/webkitinspector.py
@@ -15,13 +15,13 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
 
 """Customized QWebInspector for QtWebKit."""
 
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebSettings
 from qutebrowser.qt.webkitwidgets import QWebInspector, QWebPage
+# pylint: enable=no-name-in-module
 from qutebrowser.qt.widgets import QWidget
 
 from qutebrowser.browser import inspector
diff --git a/qutebrowser/browser/webkit/webkitsettings.py b/qutebrowser/browser/webkit/webkitsettings.py
index bd65be65b..a20811bae 100644
--- a/qutebrowser/browser/webkit/webkitsettings.py
+++ b/qutebrowser/browser/webkit/webkitsettings.py
@@ -15,9 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """Bridge from QWebSettings to our own settings.
 
 Module attributes:
@@ -30,8 +27,10 @@ import os.path
 
 from qutebrowser.qt.core import QUrl
 from qutebrowser.qt.gui import QFont
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebSettings
 from qutebrowser.qt.webkitwidgets import QWebPage
+# pylint: enable=no-name-in-module
 
 from qutebrowser.config import config, websettings
 from qutebrowser.config.websettings import AttributeInfo as Attr
diff --git a/qutebrowser/browser/webkit/webkittab.py b/qutebrowser/browser/webkit/webkittab.py
index a756e1a3d..e0483a23a 100644
--- a/qutebrowser/browser/webkit/webkittab.py
+++ b/qutebrowser/browser/webkit/webkittab.py
@@ -15,8 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
 
 """Wrapper over our (QtWebKit) WebView."""
 
@@ -28,8 +26,10 @@ from typing import cast, Iterable, Optional
 from qutebrowser.qt.core import pyqtSlot, Qt, QUrl, QPoint, QTimer, QSizeF, QSize
 from qutebrowser.qt.gui import QIcon
 from qutebrowser.qt.widgets import QWidget
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkitwidgets import QWebPage, QWebFrame
 from qutebrowser.qt.webkit import QWebSettings, QWebHistory, QWebElement
+# pylint: enable=no-name-in-module
 from qutebrowser.qt.printsupport import QPrinter
 
 from qutebrowser.browser import browsertab, shared
diff --git a/qutebrowser/browser/webkit/webpage.py b/qutebrowser/browser/webkit/webpage.py
index 27429f331..b3b1b7ceb 100644
--- a/qutebrowser/browser/webkit/webpage.py
+++ b/qutebrowser/browser/webkit/webpage.py
@@ -15,9 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """The main browser widgets."""
 
 import html
@@ -28,7 +25,9 @@ from qutebrowser.qt.gui import QDesktopServices
 from qutebrowser.qt.network import QNetworkReply, QNetworkRequest
 from qutebrowser.qt.widgets import QFileDialog
 from qutebrowser.qt.printsupport import QPrintDialog
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkitwidgets import QWebPage, QWebFrame
+# pylint: enable=no-name-in-module
 
 from qutebrowser.config import websettings, config
 from qutebrowser.browser import pdfjs, shared, downloads, greasemonkey
diff --git a/qutebrowser/browser/webkit/webview.py b/qutebrowser/browser/webkit/webview.py
index 7a08a0736..831b2b689 100644
--- a/qutebrowser/browser/webkit/webview.py
+++ b/qutebrowser/browser/webkit/webview.py
@@ -15,14 +15,13 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """The main browser widgets."""
 
 from qutebrowser.qt.core import pyqtSignal, Qt
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebSettings
 from qutebrowser.qt.webkitwidgets import QWebView, QWebPage
+# pylint: enable=no-name-in-module
 
 from qutebrowser.config import config, stylesheet
 from qutebrowser.keyinput import modeman
diff --git a/qutebrowser/html/warning-qt5.html b/qutebrowser/html/warning-qt5.html
new file mode 100644
index 000000000..17af2f72c
--- /dev/null
+++ b/qutebrowser/html/warning-qt5.html
@@ -0,0 +1,28 @@
+{% extends "styled.html" %}
+
+{% block content %}
+<h1>{{ title }}</h1>
+<span class="note">Note this warning will only appear once. Use <span class="mono">:open
+qute://warning/qt5</span> to show it again at a later time.</span>
+
+<p>
+    qutebrowser <b>now supports Qt 6</b>.
+</p>
+<p>
+    However, in your environment, <b>Qt 6 is not installed</b>. Thus, qutebrowser is still using Qt 5 instead.
+
+    Qt 5.15 based on a very old Chromium version (83 or 87, from mid/late 2020).
+</p>
+{% if is_venv %}
+<p>
+    You are using a virtualenv. If you want to use Qt 6, you need to create a new
+    virtualenv with PyQt6 installed.
+
+    If using <span class="mono">mkvenv.py</span>, <b>rerun the script</b> to create a
+    new virtualenv with Qt 6.
+</p>
+{% endif %}
+<p>
+    <span class="note">Python installation prefix: <span class="mono">{{ prefix }}</span></span>
+</p>
+{% endblock %}
diff --git a/qutebrowser/keyinput/keyutils.py b/qutebrowser/keyinput/keyutils.py
index e2a15b2c0..10f4d5378 100644
--- a/qutebrowser/keyinput/keyutils.py
+++ b/qutebrowser/keyinput/keyutils.py
@@ -37,9 +37,7 @@ from qutebrowser.qt import machinery
 from qutebrowser.qt.core import Qt, QEvent
 from qutebrowser.qt.gui import QKeySequence, QKeyEvent
 if machinery.IS_QT6:
-    # FIXME:qt6 (lint) how come pylint isn't picking this up with both backends
-    # installed?
-    from qutebrowser.qt.core import QKeyCombination  # pylint: disable=no-name-in-module
+    from qutebrowser.qt.core import QKeyCombination
 else:
     QKeyCombination = None  # QKeyCombination was added in Qt 6
 
@@ -349,7 +347,7 @@ def _unset_modifier_bits(
     https://github.com/python/cpython/issues/105497
     """
     if machinery.IS_QT5:
-        return cast(_ModifierType, modifiers & ~mask)
+        return Qt.KeyboardModifiers(modifiers & ~mask)  # can lose type if it's 0
     else:
         return Qt.KeyboardModifier(modifiers.value & ~mask.value)
 
@@ -369,11 +367,14 @@ class KeyInfo:
 
     def __post_init__(self) -> None:
         """Run some validation on the key/modifier values."""
-        # This is mainly useful while porting from Qt 5 to 6.
-        # FIXME:qt6 do we want to remove or keep this (and fix the remaining
-        # issues) when done?
-        # assert isinstance(self.key, Qt.Key), self.key
-        # assert isinstance(self.modifiers, Qt.KeyboardModifier), self.modifiers
+        # This changed with Qt 6, and e.g. to_qt() relies on this.
+        if machinery.IS_QT5:
+            modifier_classes = (Qt.KeyboardModifier, Qt.KeyboardModifiers)
+        elif machinery.IS_QT6:
+            modifier_classes = Qt.KeyboardModifier
+        assert isinstance(self.key, Qt.Key), self.key
+        assert isinstance(self.modifiers, modifier_classes), self.modifiers
+
         _assert_plain_key(self.key)
         _assert_plain_modifier(self.modifiers)
 
@@ -488,16 +489,7 @@ class KeyInfo:
         if machinery.IS_QT5:
             return int(self.key) | int(self.modifiers)
         else:
-            try:
-                # FIXME:qt6 We might want to consider only supporting KeyInfo to be
-                # instanciated with a real Qt.Key, not with ints. See __post_init__.
-                key = Qt.Key(self.key)
-            except ValueError as e:
-                # WORKAROUND for
-                # https://www.riverbankcomputing.com/pipermail/pyqt/2022-April/044607.html
-                raise InvalidKeyError(e)
-
-            return QKeyCombination(self.modifiers, key)
+            return QKeyCombination(self.modifiers, self.key)
 
     def with_stripped_modifiers(self, modifiers: Qt.KeyboardModifier) -> "KeyInfo":
         mods = _unset_modifier_bits(self.modifiers, modifiers)
diff --git a/qutebrowser/qt/_core_pyqtproperty.py b/qutebrowser/qt/_core_pyqtproperty.py
index 8ae62264f..ae6435039 100644
--- a/qutebrowser/qt/_core_pyqtproperty.py
+++ b/qutebrowser/qt/_core_pyqtproperty.py
@@ -5,7 +5,7 @@ https://github.com/python-qt-tools/PyQt5-stubs/blob/5.15.6.0/PyQt5-stubs/QtCore.
 """
 
 # flake8: noqa
-# pylint: disable=invalid-name,missing-class-docstring,too-many-arguments,redefined-builtin,unused-argument,import-error
+# pylint: disable=invalid-name,missing-class-docstring,too-many-arguments,redefined-builtin,unused-argument,no-name-in-module
 
 import typing
 from PyQt6.QtCore import QObject, pyqtSignal
diff --git a/qutebrowser/qt/machinery.py b/qutebrowser/qt/machinery.py
index e626edcb4..616c7ccfc 100644
--- a/qutebrowser/qt/machinery.py
+++ b/qutebrowser/qt/machinery.py
@@ -3,6 +3,16 @@
 """Qt wrapper selection.
 
 Contains selection logic and globals for Qt wrapper selection.
+
+All other files in this package are intended to be simple wrappers around Qt imports.
+Depending on what is set in this module, they import from PyQt5 or PyQt6.
+
+The import wrappers are intended to be as thin as possible. They will not unify
+API-level differences between Qt 5 and Qt 6. This is best handled by the calling code,
+which has a better picture of what changed between APIs and how to best handle it.
+
+What they *will* do is handle simple 1:1 renames of classes, or moves between
+modules (where they aim to always expose the Qt 6 API). See e.g. webenginecore.py.
 """
 
 # NOTE: No qutebrowser or PyQt import should be done here (at import time),
@@ -20,11 +30,11 @@ from typing import Optional, Dict
 
 from qutebrowser.utils import log
 
-# Packagers: Patch the line below to change the default wrapper for Qt 6 packages, e.g.:
-# sed -i 's/_DEFAULT_WRAPPER = "PyQt5"/_DEFAULT_WRAPPER = "PyQt6"/' qutebrowser/qt/machinery.py
+# Packagers: Patch the line below to enforce a Qt wrapper, e.g.:
+# sed -i 's/_WRAPPER_OVERRIDE = .*/_WRAPPER_OVERRIDE = "PyQt6"/' qutebrowser/qt/machinery.py
 #
 # Users: Set the QUTE_QT_WRAPPER environment variable to change the default wrapper.
-_DEFAULT_WRAPPER = "PyQt5"
+_WRAPPER_OVERRIDE = None
 
 WRAPPERS = [
     "PyQt6",
@@ -80,6 +90,9 @@ class SelectionReason(enum.Enum):
     #: The wrapper was faked/patched out (e.g. in tests).
     fake = "fake"
 
+    #: The wrapper was overridden by patching _WRAPPER_OVERRIDE.
+    override = "override"
+
     #: The reason was not set.
     unknown = "unknown"
 
@@ -152,7 +165,7 @@ def _select_wrapper(args: Optional[argparse.Namespace]) -> SelectionInfo:
 
     - If --qt-wrapper is given, use that.
     - Otherwise, if the QUTE_QT_WRAPPER environment variable is set, use that.
-    - Otherwise, use PyQt5 (FIXME:qt6 autoselect).
+    - Otherwise, try the wrappers in WRAPPER in order (PyQt6 -> PyQt5)
     """
     # If any Qt wrapper has been imported before this, something strange might
     # be happening.
@@ -170,15 +183,17 @@ def _select_wrapper(args: Optional[argparse.Namespace]) -> SelectionInfo:
         if env_wrapper == "auto":
             return _autoselect_wrapper()
         elif env_wrapper not in WRAPPERS:
-            raise Error(f"Unknown wrapper {env_wrapper} set via {env_var}, "
-                        f"allowed: {', '.join(WRAPPERS)}")
+            raise Error(
+                f"Unknown wrapper {env_wrapper} set via {env_var}, "
+                f"allowed: {', '.join(WRAPPERS)}"
+            )
         return SelectionInfo(wrapper=env_wrapper, reason=SelectionReason.env)
 
-    # FIXME:qt6 Go back to the auto-detection once ready
-    # FIXME:qt6 Make sure to still consider _DEFAULT_WRAPPER for packagers
-    # (rename to _WRAPPER_OVERRIDE since our sed command is broken anyways then?)
-    # return _autoselect_wrapper()
-    return SelectionInfo(wrapper=_DEFAULT_WRAPPER, reason=SelectionReason.default)
+    if _WRAPPER_OVERRIDE is not None:
+        assert _WRAPPER_OVERRIDE in WRAPPERS  # type: ignore[unreachable]
+        return SelectionInfo(wrapper=_WRAPPER_OVERRIDE, reason=SelectionReason.override)
+
+    return _autoselect_wrapper()
 
 
 # Values are set in init(). If you see a NameError here, it means something tried to
@@ -219,8 +234,7 @@ def _set_globals(info: SelectionInfo) -> None:
     Those are split into multiple global variables because that way we can teach mypy
     about them via --always-true and --always-false, see tox.ini.
     """
-    global INFO, USE_PYQT5, USE_PYQT6, USE_PYSIDE6, IS_QT5, IS_QT6, \
-        IS_PYQT, IS_PYSIDE, _initialized
+    global INFO, USE_PYQT5, USE_PYQT6, USE_PYSIDE6, IS_QT5, IS_QT6, IS_PYQT, IS_PYSIDE, _initialized
 
     assert info.wrapper is not None, info
     assert not _initialized
diff --git a/qutebrowser/qt/opengl.py b/qutebrowser/qt/opengl.py
index 0a14dffad..bc5a31c11 100644
--- a/qutebrowser/qt/opengl.py
+++ b/qutebrowser/qt/opengl.py
@@ -1,4 +1,4 @@
-# pylint: disable=import-error,wildcard-import,unused-import
+# pylint: disable=import-error,wildcard-import,unused-import,unused-wildcard-import
 
 """Wrapped Qt imports for Qt OpenGL.
 
diff --git a/qutebrowser/qutebrowser.py b/qutebrowser/qutebrowser.py
index e778cc23a..fcca87feb 100644
--- a/qutebrowser/qutebrowser.py
+++ b/qutebrowser/qutebrowser.py
@@ -50,7 +50,7 @@ except ImportError:
         sys.exit(100)
 check_python_version()
 
-import argparse  # FIXME:qt6 (lint): disable=wrong-import-order
+import argparse
 from qutebrowser.misc import earlyinit
 from qutebrowser.qt import machinery
 
diff --git a/scripts/dev/build_release.py b/scripts/dev/build_release.py
index 996487693..d8f9693e7 100755
--- a/scripts/dev/build_release.py
+++ b/scripts/dev/build_release.py
@@ -136,7 +136,7 @@ def _smoke_test_run(
     return subprocess.run(argv, check=True, capture_output=True)
 
 
-def smoke_test(executable: pathlib.Path, debug: bool, qt6: bool) -> None:
+def smoke_test(executable: pathlib.Path, debug: bool, qt5: bool) -> None:
     """Try starting the given qutebrowser executable."""
     stdout_whitelist = []
     stderr_whitelist = [
@@ -176,7 +176,7 @@ def smoke_test(executable: pathlib.Path, debug: bool, qt6: bool) -> None:
             r'ContextResult::kTransientFailure: Failed to send '
             r'.*CreateCommandBuffer\.'),
         ])
-        if qt6:
+        if not qt5:
             stderr_whitelist.extend([
                 # FIXME:qt6 Qt 6.3 on macOS
                 r'[0-9:]* WARNING: Incompatible version of OpenSSL',
@@ -257,10 +257,10 @@ def verify_windows_exe(exe_path: pathlib.Path) -> None:
     assert pe.verify_checksum()
 
 
-def patch_mac_app(qt6: bool) -> None:
+def patch_mac_app(qt5: bool) -> None:
     """Patch .app to save some space and make it signable."""
     dist_path = pathlib.Path('dist')
-    ver = '6' if qt6 else '5'
+    ver = '5' if qt5 else '6'
     app_path = dist_path / 'qutebrowser.app'
 
     contents_path = app_path / 'Contents'
@@ -280,7 +280,7 @@ def patch_mac_app(qt6: bool) -> None:
             file_path.unlink()
         file_path.symlink_to(target)
 
-    if qt6:
+    if not qt5:
         # Symlinking QtWebEngineCore.framework does not seem to work with Qt 6.
         # Also, the symlinking/moving before signing doesn't seem to be required.
         return
@@ -333,7 +333,7 @@ def _mac_bin_path(base: pathlib.Path) -> pathlib.Path:
 def build_mac(
     *,
     gh_token: Optional[str],
-    qt6: bool,
+    qt5: bool,
     skip_packaging: bool,
     debug: bool,
 ) -> List[Artifact]:
@@ -348,20 +348,20 @@ def build_mac(
         shutil.rmtree(d, ignore_errors=True)
 
     utils.print_title("Updating 3rdparty content")
-    update_3rdparty.run(ace=False, pdfjs=True, legacy_pdfjs=not qt6, fancy_dmg=False,
+    update_3rdparty.run(ace=False, pdfjs=True, legacy_pdfjs=qt5, fancy_dmg=False,
                         gh_token=gh_token)
 
     utils.print_title("Building .app via pyinstaller")
-    call_tox(f'pyinstaller-64bit{"-qt6" if qt6 else ""}', '-r', debug=debug)
+    call_tox(f'pyinstaller-64bit{"-qt5" if qt5 else ""}', '-r', debug=debug)
     utils.print_title("Patching .app")
-    patch_mac_app(qt6=qt6)
+    patch_mac_app(qt5=qt5)
     utils.print_title("Re-signing .app")
     sign_mac_app()
 
     dist_path = pathlib.Path("dist")
 
     utils.print_title("Running pre-dmg smoke test")
-    smoke_test(_mac_bin_path(dist_path), debug=debug, qt6=qt6)
+    smoke_test(_mac_bin_path(dist_path), debug=debug, qt5=qt5)
 
     if skip_packaging:
         return []
@@ -371,7 +371,7 @@ def build_mac(
     subprocess.run(['make', '-f', dmg_makefile_path], check=True)
 
     suffix = "-debug" if debug else ""
-    suffix += "-qt6" if qt6 else ""
+    suffix += "-qt5" if qt5 else ""
     dmg_path = dist_path / f'qutebrowser-{qutebrowser.__version__}{suffix}.dmg'
     pathlib.Path('qutebrowser.dmg').rename(dmg_path)
 
@@ -383,7 +383,7 @@ def build_mac(
             subprocess.run(['hdiutil', 'attach', dmg_path,
                             '-mountpoint', tmp_path], check=True)
             try:
-                smoke_test(_mac_bin_path(tmp_path), debug=debug, qt6=qt6)
+                smoke_test(_mac_bin_path(tmp_path), debug=debug, qt5=qt5)
             finally:
                 print("Waiting 10s for dmg to be detachable...")
                 time.sleep(10)
@@ -422,7 +422,7 @@ def _get_windows_python_path(x64: bool) -> pathlib.Path:
 
 def _build_windows_single(
     *, x64: bool,
-    qt6: bool,
+    qt5: bool,
     skip_packaging: bool,
     debug: bool,
 ) -> List[Artifact]:
@@ -437,9 +437,9 @@ def _build_windows_single(
 
     python = _get_windows_python_path(x64=x64)
     suffix = "64bit" if x64 else "32bit"
-    if qt6:
+    if qt5:
         # FIXME:qt6 does this regress 391623d5ec983ecfc4512c7305c4b7a293ac3872?
-        suffix += "-qt6"
+        suffix += "-qt5"
     call_tox(f'pyinstaller-{suffix}', '-r', python=python, debug=debug)
 
     out_pyinstaller = dist_path / "qutebrowser"
@@ -450,7 +450,7 @@ def _build_windows_single(
     verify_windows_exe(exe_path)
 
     utils.print_title(f"Running {human_arch} smoke test")
-    smoke_test(exe_path, debug=debug, qt6=qt6)
+    smoke_test(exe_path, debug=debug, qt5=qt5)
 
     if skip_packaging:
         return []
@@ -463,7 +463,7 @@ def _build_windows_single(
         desc_arch=human_arch,
         desc_suffix='' if x64 else ' (only for 32-bit Windows!)',
         debug=debug,
-        qt6=qt6,
+        qt5=qt5,
     )
 
 
@@ -472,12 +472,12 @@ def build_windows(
     skip_packaging: bool,
     only_32bit: bool,
     only_64bit: bool,
-    qt6: bool,
+    qt5: bool,
     debug: bool,
 ) -> List[Artifact]:
     """Build windows executables/setups."""
     utils.print_title("Updating 3rdparty content")
-    update_3rdparty.run(nsis=True, ace=False, pdfjs=True, legacy_pdfjs=not qt6,
+    update_3rdparty.run(nsis=True, ace=False, pdfjs=True, legacy_pdfjs=qt5,
                         fancy_dmg=False, gh_token=gh_token)
 
     utils.print_title("Building Windows binaries")
@@ -493,14 +493,14 @@ def build_windows(
             x64=True,
             skip_packaging=skip_packaging,
             debug=debug,
-            qt6=qt6,
+            qt5=qt5,
         )
-    if not only_64bit and not qt6:
+    if not only_64bit and not qt5:
         artifacts += _build_windows_single(
             x64=False,
             skip_packaging=skip_packaging,
             debug=debug,
-            qt6=qt6,
+            qt5=qt5,
         )
 
     return artifacts
@@ -514,7 +514,7 @@ def _package_windows_single(
     desc_suffix: str,
     filename_arch: str,
     debug: bool,
-    qt6: bool,
+    qt5: bool,
 ) -> List[Artifact]:
     """Build the given installer/zip for windows."""
     artifacts = []
@@ -532,8 +532,8 @@ def _package_windows_single(
     ]
     if debug:
         name_parts.append('debug')
-    if qt6:
-        name_parts.append('qt6')
+    if qt5:
+        name_parts.append('qt5')
     name = '-'.join(name_parts) + '.exe'
 
     artifacts.append(Artifact(
@@ -552,8 +552,8 @@ def _package_windows_single(
     ]
     if debug:
         zip_name_parts.append('debug')
-    if qt6:
-        zip_name_parts.append('qt6')
+    if qt5:
+        zip_name_parts.append('qt5')
     zip_name = '-'.join(zip_name_parts) + '.zip'
 
     zip_path = dist_path / zip_name
@@ -738,8 +738,8 @@ def main() -> None:
                         help="Skip Windows 32 bit build.", dest='only_64bit')
     parser.add_argument('--debug', action='store_true', required=False,
                         help="Build a debug build.")
-    parser.add_argument('--qt6', action='store_true', required=False,
-                        help="Build against PyQt6")
+    parser.add_argument('--qt5', action='store_true', required=False,
+                        help="Build against PyQt5")
     args = parser.parse_args()
     utils.change_cwd()
 
@@ -768,14 +768,14 @@ def main() -> None:
             skip_packaging=args.skip_packaging,
             only_32bit=args.only_32bit,
             only_64bit=args.only_64bit,
-            qt6=args.qt6,
+            qt5=args.qt5,
             debug=args.debug,
         )
     elif IS_MACOS:
         artifacts = build_mac(
             gh_token=gh_token,
             skip_packaging=args.skip_packaging,
-            qt6=args.qt6,
+            qt5=args.qt5,
             debug=args.debug,
         )
     else:
diff --git a/scripts/dev/misc_checks.py b/scripts/dev/misc_checks.py
index 240b5e6f1..215a1cfa0 100644
--- a/scripts/dev/misc_checks.py
+++ b/scripts/dev/misc_checks.py
@@ -27,7 +27,7 @@ import subprocess
 import tokenize
 import traceback
 import pathlib
-from typing import List, Iterator, Optional
+from typing import List, Iterator, Optional, Tuple
 
 REPO_ROOT = pathlib.Path(__file__).resolve().parents[2]
 sys.path.insert(0, str(REPO_ROOT))
@@ -152,6 +152,24 @@ def _check_spelling_file(path, fobj, patterns):
     return ok
 
 
+def _check_spelling_all(
+    args: argparse.Namespace,
+    ignored: List[pathlib.Path],
+    patterns: List[Tuple[re.Pattern, str]],
+) -> Optional[bool]:
+    try:
+        ok = True
+        for path in _get_files(verbose=args.verbose, ignored=ignored):
+            with tokenize.open(str(path)) as f:
+                if not _check_spelling_file(path, f, patterns):
+                    ok = False
+        print()
+        return ok
+    except Exception:
+        traceback.print_exc()
+        return None
+
+
 def check_spelling(args: argparse.Namespace) -> Optional[bool]:
     """Check commonly misspelled words."""
     # Words which I often misspell
@@ -273,25 +291,13 @@ def check_spelling(args: argparse.Namespace) -> Optional[bool]:
         hint_data / 'ace' / 'ace.js',
         hint_data / 'bootstrap' / 'bootstrap.css',
     ]
-
-    try:
-        ok = True
-        for path in _get_files(verbose=args.verbose, ignored=ignored):
-            with tokenize.open(path) as f:
-                if not _check_spelling_file(path, f, patterns):
-                    ok = False
-        print()
-        return ok
-    except Exception:
-        traceback.print_exc()
-        return None
+    return _check_spelling_all(args=args, ignored=ignored, patterns=patterns)
 
 
 def check_pyqt_imports(args: argparse.Namespace) -> Optional[bool]:
     """Check for direct PyQt imports."""
     ignored = [
         pathlib.Path("qutebrowser", "qt"),
-        # FIXME:qt6 fix those too?
         pathlib.Path("misc", "userscripts"),
         pathlib.Path("scripts"),
     ]
@@ -305,18 +311,7 @@ def check_pyqt_imports(args: argparse.Namespace) -> Optional[bool]:
             "Use 'import qutebrowser.qt.MODULE' instead",
         )
     ]
-    # FIXME:qt6 unify this with check_spelling somehow?
-    try:
-        ok = True
-        for path in _get_files(verbose=args.verbose, ignored=ignored):
-            with tokenize.open(str(path)) as f:
-                if not _check_spelling_file(path, f, patterns):
-                    ok = False
-        print()
-        return ok
-    except Exception:
-        traceback.print_exc()
-        return None
+    return _check_spelling_all(args=args, ignored=ignored, patterns=patterns)
 
 
 def check_vcs_conflict(args: argparse.Namespace) -> Optional[bool]:
diff --git a/scripts/dev/run_vulture.py b/scripts/dev/run_vulture.py
index 960b5a514..1e7ed0f61 100755
--- a/scripts/dev/run_vulture.py
+++ b/scripts/dev/run_vulture.py
@@ -60,7 +60,6 @@ def whitelist_generator():  # noqa: C901
     yield 'qutebrowser.misc.sql.SqliteErrorCode.CONSTRAINT'
     yield 'qutebrowser.misc.throttle.Throttle.set_delay'
     yield 'qutebrowser.misc.guiprocess.GUIProcess.stderr'
-    yield 'qutebrowser.qt.machinery._autoselect_wrapper'  # FIXME:qt6
 
     # Qt attributes
     yield 'PyQt5.QtWebKit.QWebPage.ErrorPageExtensionReturn().baseUrl'
diff --git a/scripts/dev/standardpaths_tester.py b/scripts/dev/standardpaths_tester.py
index ff85b2a4c..bbd0a39fb 100644
--- a/scripts/dev/standardpaths_tester.py
+++ b/scripts/dev/standardpaths_tester.py
@@ -21,7 +21,7 @@
 import os
 import sys
 
-from PyQt5.QtCore import (QT_VERSION_STR, PYQT_VERSION_STR, qVersion,
+from PyQt6.QtCore import (QT_VERSION_STR, PYQT_VERSION_STR, qVersion,
                           QStandardPaths, QCoreApplication)
 
 
diff --git a/scripts/keytester.py b/scripts/keytester.py
index 6d994114d..861133c06 100644
--- a/scripts/keytester.py
+++ b/scripts/keytester.py
@@ -21,8 +21,7 @@
 Use python3 -m scripts.keytester to launch it.
 """
 
-from PyQt5.QtWidgets import QApplication
-
+from qutebrowser.qt.widgets import QApplication
 from qutebrowser.misc import miscwidgets
 
 app = QApplication([])
diff --git a/scripts/link_pyqt.py b/scripts/link_pyqt.py
index 4581bef41..63bdde959 100644
--- a/scripts/link_pyqt.py
+++ b/scripts/link_pyqt.py
@@ -125,7 +125,7 @@ def get_lib_path(executable, name, required=True):
         raise ValueError("Unexpected output: {!r}".format(output))
 
 
-def link_pyqt(executable, venv_path, *, version='5'):
+def link_pyqt(executable, venv_path, *, version):
     """Symlink the systemwide PyQt/sip into the venv.
 
     Args:
diff --git a/scripts/mkvenv.py b/scripts/mkvenv.py
index 625cedd1a..9e9c1f4a2 100755
--- a/scripts/mkvenv.py
+++ b/scripts/mkvenv.py
@@ -134,8 +134,7 @@ def pyqt_versions() -> List[str]:
 
 def _is_qt6_version(version: str) -> bool:
     """Check if the given version is Qt 6."""
-    # FIXME:qt6 Adjust once auto = Qt 6
-    return version == "6" or version.startswith("6.")
+    return version in ["auto", "6"] or version.startswith("6.")
 
 
 def run_venv(
@@ -228,7 +227,7 @@ def requirements_file(name: str) -> pathlib.Path:
 
 def pyqt_requirements_file(version: str) -> pathlib.Path:
     """Get the filename of the requirements file for the given PyQt version."""
-    name = 'pyqt' if version == 'auto' else 'pyqt-{}'.format(version)
+    name = 'pyqt-6' if version == 'auto' else f'pyqt-{version}'
     return requirements_file(name)
 
 
@@ -439,7 +438,7 @@ def run_qt_smoke_test_single(
 def run_qt_smoke_test(venv_dir: pathlib.Path, *, pyqt_version: str) -> None:
     """Make sure the Qt installation works."""
     # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-104415
-    no_debug = pyqt_version in ("6.3", "6") and sys.platform == "darwin"
+    no_debug = pyqt_version == "6.3" and sys.platform == "darwin"
     if no_debug:
         try:
             run_qt_smoke_test_single(venv_dir, debug=False, pyqt_version=pyqt_version)
@@ -505,6 +504,9 @@ def install_pyqt(venv_dir, args):
         install_pyqt_binary(venv_dir, args.pyqt_version)
         if args.pyqt_snapshot:
             install_pyqt_shapshot(venv_dir, args.pyqt_snapshot.split(','))
+        # Workaround until pyqt 6.5.2 is released on pypi
+        elif args.pyqt_version in ("6.5", "6", "auto"):
+            install_pyqt_shapshot(venv_dir, ["PyQt6-Qt6", "PyQt6-WebEngine-Qt6"])
     elif args.pyqt_type == 'source':
         install_pyqt_source(venv_dir, args.pyqt_version)
     elif args.pyqt_type == 'link':
diff --git a/scripts/opengl_info.py b/scripts/opengl_info.py
index 5dc8f81c6..7c5ede6e7 100644
--- a/scripts/opengl_info.py
+++ b/scripts/opengl_info.py
@@ -18,8 +18,8 @@
 
 """Show information about the OpenGL setup."""
 
-from PyQt5.QtGui import (QOpenGLContext, QOpenGLVersionProfile,
-                         QOffscreenSurface, QGuiApplication)
+from PyQt6.QtGui import QOpenGLContext, QOffscreenSurface, QGuiApplication
+from PyQt6.QtOpenGL import QOpenGLVersionProfile, QOpenGLVersionFunctionsFactory
 
 app = QGuiApplication([])
 
@@ -38,7 +38,7 @@ print(f"GLES: {ctx.isOpenGLES()}")
 vp = QOpenGLVersionProfile()
 vp.setVersion(2, 0)
 
-vf = ctx.versionFunctions(vp)
+vf = QOpenGLVersionFunctionsFactory.get(vp, ctx)
 print(f"Vendor: {vf.glGetString(vf.GL_VENDOR)}")
 print(f"Renderer: {vf.glGetString(vf.GL_RENDERER)}")
 print(f"Version: {vf.glGetString(vf.GL_VERSION)}")
diff --git a/tests/unit/browser/webkit/test_tabhistory.py b/tests/unit/browser/webkit/test_tabhistory.py
index 047454e25..cd40af6e8 100644
--- a/tests/unit/browser/webkit/test_tabhistory.py
+++ b/tests/unit/browser/webkit/test_tabhistory.py
@@ -15,9 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """Tests for webelement.tabhistory."""
 
 import dataclasses
@@ -26,7 +23,9 @@ from typing import Any
 import pytest
 pytest.importorskip('qutebrowser.qt.webkit')
 from qutebrowser.qt.core import QUrl, QPoint
+# pylint: disable=no-name-in-module
 from qutebrowser.qt.webkit import QWebHistory
+# pylint: enable=no-name-in-module
 
 from qutebrowser.browser.webkit import tabhistory
 from qutebrowser.misc.sessions import TabHistoryItem as Item
diff --git a/tests/unit/javascript/test_js_execution.py b/tests/unit/javascript/test_js_execution.py
index 542b56975..fd2469148 100644
--- a/tests/unit/javascript/test_js_execution.py
+++ b/tests/unit/javascript/test_js_execution.py
@@ -15,9 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
 
-# FIXME:qt6 (lint)
-# pylint: disable=no-name-in-module
-
 """Check how Qt behaves when trying to execute JS."""
 
 
@@ -29,7 +26,7 @@ def test_simple_js_webkit(webview, js_enabled, expected):
     """With QtWebKit, evaluateJavaScript works when JS is on."""
     # If we get there (because of the webview fixture) we can be certain
     # QtWebKit is available
-    from qutebrowser.qt.webkit import QWebSettings
+    from qutebrowser.qt.webkit import QWebSettings  # pylint: disable=no-name-in-module
     webview.settings().setAttribute(QWebSettings.WebAttribute.JavascriptEnabled, js_enabled)
     result = webview.page().mainFrame().evaluateJavaScript('1 + 1')
     assert result == expected
@@ -40,7 +37,7 @@ def test_element_js_webkit(webview, js_enabled, expected):
     """With QtWebKit, evaluateJavaScript on an element works with JS off."""
     # If we get there (because of the webview fixture) we can be certain
     # QtWebKit is available
-    from qutebrowser.qt.webkit import QWebSettings
+    from qutebrowser.qt.webkit import QWebSettings  # pylint: disable=no-name-in-module
     webview.settings().setAttribute(QWebSettings.WebAttribute.JavascriptEnabled, js_enabled)
     elem = webview.page().mainFrame().documentElement()
     result = elem.evaluateJavaScript('1 + 1')
diff --git a/tests/unit/keyinput/key_data.py b/tests/unit/keyinput/key_data.py
index 3826d3ee9..5f151704a 100644
--- a/tests/unit/keyinput/key_data.py
+++ b/tests/unit/keyinput/key_data.py
@@ -24,6 +24,7 @@ import dataclasses
 from typing import Optional
 
 from qutebrowser.qt.core import Qt
+from qutebrowser.keyinput import keyutils
 
 
 @dataclasses.dataclass(order=True)
@@ -606,7 +607,7 @@ KEYS = [
 
     Key('unknown', 'Unknown', qtest=False),
     # 0x0 is used by Qt for unknown keys...
-    Key(attribute='', name='nil', member=0x0, qtest=False),
+    Key(attribute='', name='nil', member=keyutils._NIL_KEY, qtest=False),
 ]
 
 
diff --git a/tests/unit/keyinput/test_basekeyparser.py b/tests/unit/keyinput/test_basekeyparser.py
index 52e0a01df..0ae0702e9 100644
--- a/tests/unit/keyinput/test_basekeyparser.py
+++ b/tests/unit/keyinput/test_basekeyparser.py
@@ -171,7 +171,7 @@ class TestHandle:
         assert not prompt_keyparser._count
 
     def test_invalid_key(self, prompt_keyparser):
-        keys = [Qt.Key.Key_B, 0x0]
+        keys = [Qt.Key.Key_B, keyutils._NIL_KEY]
         for key in keys:
             info = keyutils.KeyInfo(key, Qt.KeyboardModifier.NoModifier)
             prompt_keyparser.handle(info.to_event())
diff --git a/tests/unit/keyinput/test_keyutils.py b/tests/unit/keyinput/test_keyutils.py
index 2c0740c20..c3b6dc236 100644
--- a/tests/unit/keyinput/test_keyutils.py
+++ b/tests/unit/keyinput/test_keyutils.py
@@ -31,6 +31,16 @@ from qutebrowser.keyinput import keyutils
 from qutebrowser.utils import utils
 
 
+pyqt_enum_workaround_skip = pytest.mark.skipif(
+    isinstance(keyutils._NIL_KEY, int),
+    reason="Can't create QKey for unknown keys with this PyQt version"
+)
+try:
+    OE_KEY = Qt.Key(ord('Œ'))
+except ValueError:
+    OE_KEY = None  # affected tests skipped
+
+
 @pytest.fixture(params=key_data.KEYS, ids=lambda k: k.attribute)
 def qt_key(request):
     """Get all existing keys from key_data.py.
@@ -156,10 +166,14 @@ class TestKeyToString:
     (Qt.Key.Key_A,
      Qt.KeyboardModifier.ControlModifier | Qt.KeyboardModifier.AltModifier | Qt.KeyboardModifier.MetaModifier | Qt.KeyboardModifier.ShiftModifier,
      '<Meta+Ctrl+Alt+Shift+a>'),
-    (ord('Œ'), Qt.KeyboardModifier.NoModifier, '<Œ>'),
-    (ord('Œ'), Qt.KeyboardModifier.ShiftModifier, '<Shift+Œ>'),
-    (ord('Œ'), Qt.KeyboardModifier.GroupSwitchModifier, '<AltGr+Œ>'),
-    (ord('Œ'), Qt.KeyboardModifier.GroupSwitchModifier | Qt.KeyboardModifier.ShiftModifier, '<AltGr+Shift+Œ>'),
+
+    pytest.param(OE_KEY, Qt.KeyboardModifier.NoModifier, '<Œ>',
+                 marks=pyqt_enum_workaround_skip),
+    pytest.param(OE_KEY, Qt.KeyboardModifier.ShiftModifier, '<Shift+Œ>',
+                 marks=pyqt_enum_workaround_skip),
+    pytest.param(OE_KEY, Qt.KeyboardModifier.GroupSwitchModifier, '<AltGr+Œ>',
+                 marks=pyqt_enum_workaround_skip),
+    pytest.param(OE_KEY, Qt.KeyboardModifier.GroupSwitchModifier | Qt.KeyboardModifier.ShiftModifier, '<AltGr+Shift+Œ>'),
 
     (Qt.Key.Key_Shift, Qt.KeyboardModifier.ShiftModifier, '<Shift>'),
     (Qt.Key.Key_Shift, Qt.KeyboardModifier.ShiftModifier | Qt.KeyboardModifier.ControlModifier, '<Ctrl+Shift>'),
@@ -212,10 +226,10 @@ def test_surrogates(key, modifiers, text, expected, pyqt_enum_workaround):
     ([Qt.Key.Key_Shift, 0x29df6], '<Shift><𩷶>'),
     ([0x1f468, 0x200d, 0x1f468, 0x200d, 0x1f466], '<👨><‍><👨><‍><👦>'),
 ])
-def test_surrogate_sequences(keys, expected, pyqt_enum_workaround):
-    infos = [keyutils.KeyInfo(key) for key in keys]
-    with pyqt_enum_workaround(keyutils.KeyParseError):
-        seq = keyutils.KeySequence(*infos)
+@pyqt_enum_workaround_skip
+def test_surrogate_sequences(keys, expected):
+    infos = [keyutils.KeyInfo(Qt.Key(key)) for key in keys]
+    seq = keyutils.KeySequence(*infos)
     assert str(seq) == expected
 
 
@@ -590,7 +604,8 @@ def test_key_info_to_qt():
     (Qt.Key.Key_Return, False),
     (Qt.Key.Key_Enter, False),
     (Qt.Key.Key_Space, False),
-    (0x0, False),  # Used by Qt for unknown keys
+    # Used by Qt for unknown keys
+    pytest.param(keyutils._NIL_KEY, False, marks=pyqt_enum_workaround_skip),
 
     (Qt.Key.Key_ydiaeresis, True),
     (Qt.Key.Key_X, True),
diff --git a/tests/unit/test_qt_machinery.py b/tests/unit/test_qt_machinery.py
index 1618e9e6f..32f63043b 100644
--- a/tests/unit/test_qt_machinery.py
+++ b/tests/unit/test_qt_machinery.py
@@ -23,6 +23,7 @@ import html
 import argparse
 import typing
 from typing import Any, Optional, List, Dict, Union
+import dataclasses
 
 import pytest
 
@@ -214,7 +215,7 @@ def modules():
                 reason=machinery.SelectionReason.auto,
                 outcomes={
                     "PyQt6": "ImportError: Fake ImportError for PyQt6.",
-                }
+                },
             ),
             id="import-error",
         ),
@@ -230,111 +231,157 @@ def test_autoselect(
     assert machinery._autoselect_wrapper() == expected
 
 
-@pytest.mark.parametrize(
-    "args, env, expected",
-    [
-        # Defaults with no overrides
-        (
-            None,
-            None,
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.default
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper=None),
-            None,
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.default
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper=None),
-            "",
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.default
-            ),
-        ),
-        # Only argument given
-        (
-            argparse.Namespace(qt_wrapper="PyQt6"),
-            None,
-            machinery.SelectionInfo(
-                wrapper="PyQt6", reason=machinery.SelectionReason.cli
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper="PyQt5"),
-            None,
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.cli
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper="PyQt5"),
-            "",
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.cli
-            ),
-        ),
-        # Only environment variable given
-        (
-            None,
-            "PyQt6",
-            machinery.SelectionInfo(
-                wrapper="PyQt6", reason=machinery.SelectionReason.env
-            ),
-        ),
-        (
-            None,
-            "PyQt5",
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.env
-            ),
-        ),
-        # Both given
-        (
-            argparse.Namespace(qt_wrapper="PyQt5"),
-            "PyQt6",
-            machinery.SelectionInfo(
-                wrapper="PyQt5", reason=machinery.SelectionReason.cli
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper="PyQt6"),
-            "PyQt5",
-            machinery.SelectionInfo(
-                wrapper="PyQt6", reason=machinery.SelectionReason.cli
-            ),
-        ),
-        (
-            argparse.Namespace(qt_wrapper="PyQt6"),
-            "PyQt6",
-            machinery.SelectionInfo(
-                wrapper="PyQt6", reason=machinery.SelectionReason.cli
-            ),
-        ),
-    ],
-)
-def test_select_wrapper(
-    args: Optional[argparse.Namespace],
-    env: Optional[str],
-    expected: machinery.SelectionInfo,
-    monkeypatch: pytest.MonkeyPatch,
-    undo_init: None,
-):
-    if env is None:
-        monkeypatch.delenv("QUTE_QT_WRAPPER", raising=False)
-    else:
-        monkeypatch.setenv("QUTE_QT_WRAPPER", env)
+@dataclasses.dataclass
+class SelectWrapperCase:
+    name: str
+    expected: machinery.SelectionInfo
+    args: Optional[argparse.Namespace] = None
+    env: Optional[str] = None
+    override: Optional[str] = None
 
-    assert machinery._select_wrapper(args) == expected
+    def __str__(self):
+        return self.name
 
 
-def test_select_wrapper_after_qt_import(monkeypatch: pytest.MonkeyPatch):
-    monkeypatch.setitem(sys.modules, "PyQt6", None)
-    with pytest.warns(UserWarning, match="PyQt6 already imported"):
-        machinery._select_wrapper(args=None)
+class TestSelectWrapper:
+    @pytest.mark.parametrize(
+        "tc",
+        [
+            # Only argument given
+            SelectWrapperCase(
+                "pyqt6-arg",
+                args=argparse.Namespace(qt_wrapper="PyQt6"),
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt6", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            SelectWrapperCase(
+                "pyqt5-arg",
+                args=argparse.Namespace(qt_wrapper="PyQt5"),
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            SelectWrapperCase(
+                "pyqt6-arg-empty-env",
+                args=argparse.Namespace(qt_wrapper="PyQt5"),
+                env="",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            # Only environment variable given
+            SelectWrapperCase(
+                "pyqt6-env",
+                env="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt6", reason=machinery.SelectionReason.env
+                ),
+            ),
+            SelectWrapperCase(
+                "pyqt5-env",
+                env="PyQt5",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.env
+                ),
+            ),
+            # Both given
+            SelectWrapperCase(
+                "pyqt5-arg-pyqt6-env",
+                args=argparse.Namespace(qt_wrapper="PyQt5"),
+                env="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            SelectWrapperCase(
+                "pyqt6-arg-pyqt5-env",
+                args=argparse.Namespace(qt_wrapper="PyQt6"),
+                env="PyQt5",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt6", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            SelectWrapperCase(
+                "pyqt6-arg-pyqt6-env",
+                args=argparse.Namespace(qt_wrapper="PyQt6"),
+                env="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt6", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            # Override
+            SelectWrapperCase(
+                "override-only",
+                override="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt6", reason=machinery.SelectionReason.override
+                ),
+            ),
+            SelectWrapperCase(
+                "override-arg",
+                args=argparse.Namespace(qt_wrapper="PyQt5"),
+                override="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.cli
+                ),
+            ),
+            SelectWrapperCase(
+                "override-env",
+                env="PyQt5",
+                override="PyQt6",
+                expected=machinery.SelectionInfo(
+                    wrapper="PyQt5", reason=machinery.SelectionReason.env
+                ),
+            ),
+        ],
+        ids=str,
+    )
+    def test_select(self, tc: SelectWrapperCase, monkeypatch: pytest.MonkeyPatch):
+        if tc.env is None:
+            monkeypatch.delenv("QUTE_QT_WRAPPER", raising=False)
+        else:
+            monkeypatch.setenv("QUTE_QT_WRAPPER", tc.env)
+
+        if tc.override is not None:
+            monkeypatch.setattr(machinery, "_WRAPPER_OVERRIDE", tc.override)
+
+        assert machinery._select_wrapper(tc.args) == tc.expected
+
+    @pytest.mark.parametrize(
+        "args, env",
+        [
+            (None, None),
+            (argparse.Namespace(qt_wrapper=None), None),
+            (argparse.Namespace(qt_wrapper=None), ""),
+        ],
+    )
+    def test_autoselect_by_default(
+        self,
+        args: Optional[argparse.Namespace],
+        env: Optional[str],
+        monkeypatch: pytest.MonkeyPatch,
+    ):
+        """Test that the default behavior is to autoselect a wrapper.
+
+        Autoselection itself is tested further down.
+        """
+        if env is None:
+            monkeypatch.delenv("QUTE_QT_WRAPPER", raising=False)
+        else:
+            monkeypatch.setenv("QUTE_QT_WRAPPER", env)
+
+        assert machinery._select_wrapper(args).reason == machinery.SelectionReason.auto
+
+    def test_after_qt_import(self, monkeypatch: pytest.MonkeyPatch):
+        monkeypatch.setitem(sys.modules, "PyQt6", None)
+        with pytest.warns(UserWarning, match="PyQt6 already imported"):
+            machinery._select_wrapper(args=None)
+
+    def test_invalid_override(self, monkeypatch: pytest.MonkeyPatch):
+        monkeypatch.setattr(machinery, "_WRAPPER_OVERRIDE", "invalid")
+        with pytest.raises(AssertionError):
+            machinery._select_wrapper(args=None)
 
 
 class TestInit:
@@ -359,15 +406,34 @@ class TestInit:
         ):
             machinery.init(args=empty_args)
 
+    @pytest.fixture(params=["auto", "", None])
+    def qt_auto_env(
+        self,
+        request: pytest.FixtureRequest,
+        monkeypatch: pytest.MonkeyPatch,
+    ):
+        """Trigger wrapper autoselection via environment variable.
+
+        Autoselection should be used in three scenarios:
+
+        - The environment variable is set to "auto".
+        - The environment variable is set to an empty string.
+        - The environment variable is not set at all.
+
+        We run test_none_available_*() for all three scenarios.
+        """
+        if request.param is None:
+            monkeypatch.delenv("QUTE_QT_WRAPPER", raising=False)
+        else:
+            monkeypatch.setenv("QUTE_QT_WRAPPER", request.param)
+
     def test_none_available_implicit(
         self,
         stubs: Any,
         modules: Dict[str, bool],
         monkeypatch: pytest.MonkeyPatch,
-        undo_init: None,
+        qt_auto_env: None,
     ):
-        # FIXME:qt6 Also try without this once auto is default
-        monkeypatch.setenv("QUTE_QT_WRAPPER", "auto")
         stubs.ImportFake(modules, monkeypatch).patch()
 
         message_lines = [
@@ -391,10 +457,8 @@ class TestInit:
         modules: Dict[str, bool],
         monkeypatch: pytest.MonkeyPatch,
         empty_args: argparse.Namespace,
-        undo_init: None,
+        qt_auto_env: None,
     ):
-        # FIXME:qt6 Also try without this once auto is default
-        monkeypatch.setenv("QUTE_QT_WRAPPER", "auto")
         stubs.ImportFake(modules, monkeypatch).patch()
 
         info = machinery.init(args=empty_args)
@@ -403,7 +467,7 @@ class TestInit:
             reason=machinery.SelectionReason.auto,
             outcomes={
                 "PyQt6": "ImportError: Fake ImportError for PyQt6.",
-            }
+            },
         )
 
     @pytest.mark.parametrize(
@@ -422,7 +486,6 @@ class TestInit:
         true_vars: str,
         explicit: bool,
         empty_args: argparse.Namespace,
-        undo_init: None,
     ):
         info = machinery.SelectionInfo(
             wrapper=selected_wrapper,
diff --git a/tox.ini b/tox.ini
index bf1c6efa2..74eb5213a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,10 +11,10 @@ minversion = 3.20
 
 [testenv]
 setenv =
-    PYTEST_QT_API=pyqt5
-    QUTE_QT_WRAPPER=PyQt5
-    pyqt{62,63,64,65}: PYTEST_QT_API=pyqt6
-    pyqt{62,63,64,65}: QUTE_QT_WRAPPER=PyQt6
+    PYTEST_QT_API=pyqt6
+    QUTE_QT_WRAPPER=PyQt6
+    pyqt{515,5152}: PYTEST_QT_API=pyqt5
+    pyqt{515,5152}: QUTE_QT_WRAPPER=PyQt5
     cov: PYTEST_ADDOPTS=--cov --cov-report xml --cov-report=html --cov-report=
     py312: VIRTUALENV_PIP=23.2
     py312: PIP_REQUIRE_VIRTUALENV=0
@@ -56,10 +56,10 @@ commands =
     {envpython} -bb -m pytest {posargs:tests}
     cov: {envpython} scripts/dev/check_coverage.py {posargs}
 
-[testenv:py-qt6]
+[testenv:py-qt5]
 setenv =
-    PYTEST_QT_API=pyqt6
-    QUTE_QT_WRAPPER=PyQt6
+    PYTEST_QT_API=pyqt5
+    QUTE_QT_WRAPPER=PyQt5
 
 [testenv:bleeding]
 basepython = {env:PYTHON:python3}
@@ -112,6 +112,7 @@ deps =
     -r{toxinidir}/misc/requirements/requirements-tests.txt
     -r{toxinidir}/misc/requirements/requirements-pylint.txt
     -r{toxinidir}/misc/requirements/requirements-pyqt.txt
+    -r{toxinidir}/misc/requirements/requirements-pyqt-5.txt
 commands =
     {envpython} -m pylint scripts qutebrowser --output-format=colorized --reports=no {posargs}
     {envpython} scripts/dev/run_pylint_on_tests.py {toxinidir} --output-format=colorized --reports=no {posargs}
@@ -180,19 +181,19 @@ commands =
     {envpython} scripts/dev/check_doc_changes.py {posargs}
     {envpython} scripts/asciidoc2html.py {posargs}
 
-[testenv:pyinstaller-{64bit,32bit}{,-qt6}]
+[testenv:pyinstaller-{64bit,32bit}{,-qt5}]
 basepython = {env:PYTHON:python3}
 passenv =
     APPDATA
     HOME
     PYINSTALLER_DEBUG
 setenv =
-    qt6: PYINSTALLER_QT6=true
+    qt5: PYINSTALLER_QT5=true
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/misc/requirements/requirements-pyinstaller.txt
-    !qt6: -r{toxinidir}/misc/requirements/requirements-pyqt.txt
-    qt6: -r{toxinidir}/misc/requirements/requirements-pyqt-6.txt
+    !qt5: -r{toxinidir}/misc/requirements/requirements-pyqt-6.txt
+    qt5: -r{toxinidir}/misc/requirements/requirements-pyqt-5.txt
 commands =
     {envbindir}/pyinstaller --noconfirm misc/qutebrowser.spec
 
@@ -246,9 +247,7 @@ commands =
 basepython = {env:PYTHON:python3}
 passenv = {[testenv:mypy-pyqt6]passenv}
 deps = {[testenv:mypy-pyqt6]deps}
-setenv =
-    pyqt6: QUTE_CONSTANTS_ARGS=--always-true=USE_PYQT6 --always-false=USE_PYQT5 --always-false=USE_PYSIDE2 --always-false=USE_PYSIDE6 --always-false=IS_QT5 --always-true=IS_QT6
-    pyqt5: QUTE_CONSTANTS_ARGS=--always-false=USE_PYQT6 --always-true=USE_PYQT5 --always-false=USE_PYSIDE2 --always-false=USE_PYSIDE6 --always-true=IS_QT5 --always-false=IS_QT6
+setenv = {[testenv:mypy-pyqt6]setenv}
 commands =
     {envpython} -m mypy --cobertura-xml-report {envtmpdir} {env:QUTE_CONSTANTS_ARGS} qutebrowser tests {posargs}
     {envdir}/bin/diff-cover --fail-under=100 --compare-branch={env:DIFF_BRANCH:origin/{env:GITHUB_BASE_REF:master}} {envtmpdir}/cobertura.xml
@@ -264,21 +263,21 @@ deps =
 commands =
     {envpython} -m sphinx -jauto -W --color {posargs} {toxinidir}/doc/extapi/ {toxinidir}/doc/extapi/_build/
 
-[testenv:build-release{,-qt6}]
+[testenv:build-release{,-qt5}]
 basepython = {env:PYTHON:python3}
 passenv = *
-# Override default PyQt5 from [testenv]
+# Override default PyQt6 from [testenv]
 setenv =
-    qt6: QUTE_QT_WRAPPER=PyQt6
+    qt5: QUTE_QT_WRAPPER=PyQt5
 usedevelop = true
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/misc/requirements/requirements-tox.txt
     -r{toxinidir}/misc/requirements/requirements-docs.txt
-    !qt6: -r{toxinidir}/misc/requirements/requirements-pyqt.txt
-    qt6: -r{toxinidir}/misc/requirements/requirements-pyqt-6.txt
+    !qt5: -r{toxinidir}/misc/requirements/requirements-pyqt.txt
+    qt5: -r{toxinidir}/misc/requirements/requirements-pyqt-5.txt
     -r{toxinidir}/misc/requirements/requirements-dev.txt
     -r{toxinidir}/misc/requirements/requirements-pyinstaller.txt
 commands =
-    !qt6: {envpython} {toxinidir}/scripts/dev/build_release.py {posargs}
-    qt6: {envpython} {toxinidir}/scripts/dev/build_release.py --qt6 {posargs}
+    !qt5: {envpython} {toxinidir}/scripts/dev/build_release.py {posargs}
+    qt5: {envpython} {toxinidir}/scripts/dev/build_release.py --qt5 {posargs}