diff --git a/environment.yml b/environment.yml
new file mode 100644
index 00000000..6b437b49
--- /dev/null
+++ b/environment.yml
@@ -0,0 +1,5 @@
+name: vitables-dev
+dependencies:
+  - python=3.11
+  - h5py
+  - ipython
diff --git a/setup.py b/setup.py
index 978e14b1..0ea920a3 100644
--- a/setup.py
+++ b/setup.py
@@ -29,10 +29,8 @@ def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read()
 
 
-install_requires = ['qtpy (>=1.2.1)', 'numpy (>=1.4.1)', 'numexpr (>=2.0)',
+install_requires = ['qtpy', 'pyqt6', 'numpy (>=1.4.1)', 'numexpr (>=2.0)',
                     'tables (>=3.0)', 'setuptools']
-if 'CONDA_PREFIX' not in os.environ:
-    install_requires.append('PyQt5 (>=5.5.1)')
 
 setup(name='ViTables',
       version=read('VERSION').rstrip('\r\n'),
diff --git a/tests/test_vtconfig.py b/tests/test_vtconfig.py
index 794da285..feae5651 100644
--- a/tests/test_vtconfig.py
+++ b/tests/test_vtconfig.py
@@ -20,7 +20,7 @@ def config(self, launcher):
         # Tear down code
         cfg.writeValue('Logger/Paper', QtGui.QColor("#ffffff"))
         cfg.writeValue('Logger/Text', QtGui.QColor("#000000"))
-        cfg.writeValue('Logger/Font', QtWidgets.qApp.font())
+        cfg.writeValue('Logger/Font', QtWidgets.QApplication.font())
         cfg.writeValue('Workspace/Background',
                        QtGui.QBrush(QtGui.QColor("#ffffff")))
         cfg.writeValue('Look/currentStyle', cfg.default_style)
diff --git a/vitables/csv/export_csv.py b/vitables/csv/export_csv.py
index 41718103..f14be4be 100644
--- a/vitables/csv/export_csv.py
+++ b/vitables/csv/export_csv.py
@@ -264,7 +264,7 @@ def export(self):
             filepath, add_header = export_info
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             with open(filepath, 'ab') as out_handler:
                 if add_header:
                     from functools import reduce
@@ -280,7 +280,7 @@ def export(self):
                 # we must explicitly ensure we get an integer
                 nchunks = numpy.floor_divide(nrows, chunk_size)
                 for i in numpy.arange(0, nchunks + 1):
-                    QtWidgets.qApp.processEvents()
+                    QtWidgets.QApplication.processEvents()
                     cstart = chunk_size * i
                     if cstart >= nrows:
                         break
@@ -292,4 +292,4 @@ def export(self):
         except OSError:
             vitables.utils.formatExceptionInfo()
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
diff --git a/vitables/csv/import_csv.py b/vitables/csv/import_csv.py
index a0eaf4d7..c1fc9d1f 100644
--- a/vitables/csv/import_csv.py
+++ b/vitables/csv/import_csv.py
@@ -266,8 +266,8 @@ def csv2Table(self):
 
         # Import the CSV content
         try:
-            QtWidgets.qApp.processEvents()
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.processEvents()
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             input_handler = open(filepath, 'r+')
             try:
                 (nrows, descr, has_header) = csvutils.tableInfo(input_handler)
@@ -306,7 +306,7 @@ def csv2Table(self):
         except:
             vitables.utils.formatExceptionInfo()
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
             input_handler.close()
 
     def csv2EArray(self):
@@ -322,8 +322,8 @@ def csv2EArray(self):
 
         # Import the CSV content
         try:
-            QtWidgets.qApp.processEvents()
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.processEvents()
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             chunk_size = 10000
             input_handler = open(filepath, 'r+')
             (nrows, atom, array_shape) = csvutils.earrayInfo(input_handler)
@@ -359,7 +359,7 @@ def csv2EArray(self):
         except:
             vitables.utils.formatExceptionInfo()
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
             input_handler.close()
 
     def csv2CArray(self):
@@ -375,8 +375,8 @@ def csv2CArray(self):
 
         # Import the CSV content
         try:
-            QtWidgets.qApp.processEvents()
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.processEvents()
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             chunk_size = 10000
             input_handler = open(filepath, 'r+')
             (atom, array_shape) = csvutils.carrayInfo(input_handler)
@@ -415,7 +415,7 @@ def csv2CArray(self):
         except:
             vitables.utils.formatExceptionInfo()
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
             input_handler.close()
 
     def csv2Array(self):
@@ -431,8 +431,8 @@ def csv2Array(self):
 
         # Import the CSV content
         try:
-            QtWidgets.qApp.processEvents()
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.processEvents()
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             # The dtypes are determined by the contents of each column
             # Multidimensional columns will have string datatype
             data = numpy.genfromtxt(filepath, delimiter=',', dtype=None)
@@ -458,4 +458,4 @@ def csv2Array(self):
                 vitables.utils.formatExceptionInfo()
         finally:
             del data
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
diff --git a/vitables/h5db/dbstreemodel.py b/vitables/h5db/dbstreemodel.py
index b1df24c3..029d6908 100644
--- a/vitables/h5db/dbstreemodel.py
+++ b/vitables/h5db/dbstreemodel.py
@@ -284,7 +284,7 @@ def createDBDoc(self, filepath, is_tmp_db=False):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(
+            QtWidgets.QApplication.setOverrideCursor(
                 QtGui.QCursor(QtCore.Qt.WaitCursor))
             # Create the dbdoc
             try:
@@ -311,7 +311,7 @@ def createDBDoc(self, filepath, is_tmp_db=False):
             self.links_delta = frozenset([])
             self.insertRows(0, 1)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
         return db_doc
 
     def __createTempDB(self):
@@ -342,7 +342,7 @@ def deleteNode(self, index):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             node = self.nodeFromIndex(index)
             # Deletes the node from the database
             node.editor().delete(node.nodepath)
@@ -363,7 +363,7 @@ def deleteNode(self, index):
             except KeyError:
                 pass
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def copy_node(self, index):
         """Mark a node from the tree of databases view as copied.
@@ -372,7 +372,7 @@ def copy_node(self, index):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             node = self.nodeFromIndex(index)
             self.ccni = {'is_copied': True,
                          'nodename': node.name,
@@ -380,7 +380,7 @@ def copy_node(self, index):
                          'nodepath': node.nodepath,
                          'target': getattr(node, 'target', None)}
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def cutNode(self, index):
         """Cut a `tables.Node`.
@@ -391,7 +391,7 @@ def cutNode(self, index):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             node = self.nodeFromIndex(index)
             self.ccni = {'is_copied': False,
                          'nodename': node.name,
@@ -414,7 +414,7 @@ def cutNode(self, index):
                 current = self.index(position - 1, 0, parent)
             self.vtgui.dbs_tree_view.selectNode(current)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def pasteNode(self, index, childname, overwrite=False):
         """Paste a tables.Node.
@@ -429,7 +429,7 @@ def pasteNode(self, index, childname, overwrite=False):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             parent = self.nodeFromIndex(index)
 
             # If the overwritten node (if any) exists in the tree of
@@ -454,7 +454,7 @@ def pasteNode(self, index, childname, overwrite=False):
             # Select the pasted node
             self.selectIndex(index, childname)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def copiedNode(self):
         """The tables.Node currently copied/cut.
@@ -481,7 +481,7 @@ def create_group(self, index, childname, overwrite=False):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             parent = self.nodeFromIndex(index)
             # If the overwritten node (if any) exists in the tree of
             # databases view then delete it
@@ -498,7 +498,7 @@ def create_group(self, index, childname, overwrite=False):
             # Select the pasted node
             self.selectIndex(index, childname)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def rename_node(self, index, new_name, overwrite=False):
         """Rename a node.
@@ -511,7 +511,7 @@ def rename_node(self, index, new_name, overwrite=False):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             node = self.nodeFromIndex(index)
             initial_nodepath = node.nodepath
             parent_index = self.parent(index)
@@ -534,7 +534,7 @@ def rename_node(self, index, new_name, overwrite=False):
             except KeyError:
                 pass
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
     def updateDBTree(self, index, new_name, node):
         """
@@ -595,7 +595,7 @@ def move_node(self, src_filepath, childpath, parent_index, overwrite=False):
         """
 
         try:
-            QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
             parent_node = self.nodeFromIndex(parent_index)
             # full path of the destination database and new parent
             dst_filepath = parent_node.filepath
@@ -624,7 +624,7 @@ def move_node(self, src_filepath, childpath, parent_index, overwrite=False):
             movedname = editor.move(childpath, self.getDBDoc(dst_filepath),
                                     parentpath, nodename)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
             return movedname
 
     def validateNodename(self, src_filepath, childpath, dst_filepath,
diff --git a/vitables/preferences/vtconfig.py b/vitables/preferences/vtconfig.py
index 041a7507..c570ad4f 100644
--- a/vitables/preferences/vtconfig.py
+++ b/vitables/preferences/vtconfig.py
@@ -137,9 +137,9 @@ def __init__(self):
         is UserScope.
         """
 
-        organization = QtWidgets.qApp.organizationName()
-        product = QtWidgets.qApp.applicationName()
-        version = QtWidgets.qApp.applicationVersion()
+        organization = QtWidgets.QApplication.organizationName()
+        product = QtWidgets.QApplication.applicationName()
+        version = QtWidgets.QApplication.applicationVersion()
         if sys.platform.startswith('win'):
             # organizationName() -> product
             # applicationName() -> version
@@ -206,7 +206,7 @@ def loggerFont(self):
         """
 
         key = 'Logger/Font'
-        default_value = QtWidgets.qApp.font()
+        default_value = QtWidgets.QApplication.font()
         setting_value = self.value(key)
         if isinstance(setting_value, QtGui.QFont):
             return setting_value
@@ -570,7 +570,7 @@ def applyUserPreferences(self, config):
         if key in config:
             self.current_style = config[key]
             # Default style is provided by the underlying window manager
-            QtWidgets.qApp.setStyle(self.current_style)
+            QtWidgets.QApplication.setStyle(self.current_style)
 
         key = 'Plugins/Enabled'
         if key in config:
diff --git a/vitables/queries/query.py b/vitables/queries/query.py
index a858cdc6..672ae3d6 100644
--- a/vitables/queries/query.py
+++ b/vitables/queries/query.py
@@ -131,7 +131,7 @@ def queryWithIndex(self, src_dict):
         # Selection is done in several steps. It saves a *huge*
         # amount of memory when querying large tables
         for i in numpy.arange(0, div+1):
-            QtWidgets.qApp.processEvents()
+            QtWidgets.QApplication.processEvents()
             lstart = start + chunk_size*i
             if lstart > stop:
                 lstart = stop
@@ -187,7 +187,7 @@ def queryWithNoIndex(self, src_dict):
         # Selection is done in several steps. It saves a *huge*
         # amount of memory when querying large tables
         for i in numpy.arange(0, div+1):
-            QtWidgets.qApp.processEvents()
+            QtWidgets.QApplication.processEvents()
             lstart = start + chunk_size*i
             if lstart > stop:
                 lstart = stop
diff --git a/vitables/queries/querydlg.py b/vitables/queries/querydlg.py
index 2202edca..cca217b1 100644
--- a/vitables/queries/querydlg.py
+++ b/vitables/queries/querydlg.py
@@ -115,7 +115,7 @@ def __init__(self, info, ft_names, counter, initial_query, table):
         #
         # Create the dialog and customise the content of some widgets
         #
-        super(QueryDlg, self).__init__(QtWidgets.qApp.activeWindow())
+        super(QueryDlg, self).__init__(QtWidgets.QApplication.activeWindow())
         self.setupUi(self)
 
         self.setWindowTitle(translate('QueryDlg', 'New query on table: {0}',
diff --git a/vitables/queries/querymgr.py b/vitables/queries/querymgr.py
index 4e3b6d16..26fd062b 100644
--- a/vitables/queries/querymgr.py
+++ b/vitables/queries/querymgr.py
@@ -199,7 +199,7 @@ def newQuery(self):
         new_query = query.Query(tmp_h5file, table_uid, table,
                                 query_description)
         new_query.query_completed.connect(self.addQueryResult)
-        QtWidgets.qApp.setOverrideCursor(QtCore.Qt.WaitCursor)
+        QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
         new_query.run()
 
     def getQueryInfo(self, info, table):
@@ -231,7 +231,7 @@ def getQueryInfo(self, info, table):
         finally:
             query_description = dict(query_dlg.query_info)
             del query_dlg
-            QtWidgets.qApp.processEvents()
+            QtWidgets.QApplication.processEvents()
 
         if not query_description['condition']:
             return None
@@ -298,7 +298,7 @@ def addQueryResult(self, completed, table_uid):
         - `table_uid`: the UID of the table just queried
         """
 
-        QtWidgets.qApp.restoreOverrideCursor()
+        QtWidgets.QApplication.restoreOverrideCursor()
         if not completed:
             log.error(translate('QueriesManager',
                                 'Query on table {0} failed!',
diff --git a/vitables/utils.py b/vitables/utils.py
index 51414e16..11f616ee 100644
--- a/vitables/utils.py
+++ b/vitables/utils.py
@@ -56,7 +56,7 @@ def getVTApp():
     """
 
     vtapp = None
-    for widget in QtWidgets.qApp.topLevelWidgets():
+    for widget in QtWidgets.QApplication.topLevelWidgets():
         if widget.objectName() == 'VTGUI':
             vtapp = widget.vtapp
             break
diff --git a/vitables/vtapp.py b/vitables/vtapp.py
index d239e0c7..d389b878 100644
--- a/vitables/vtapp.py
+++ b/vitables/vtapp.py
@@ -550,12 +550,12 @@ def fileSaveAs(self):
 
         # Make a copy of the selected file
         try:
-            QtWidgets.qApp.setOverrideCursor(
+            QtWidgets.QApplication.setOverrideCursor(
                 QtGui.QCursor(QtCore.Qt.WaitCursor))
             dbdoc = self.gui.dbs_tree_model.getDBDoc(initial_filepath)
             dbdoc.copy_file(filepath)
         finally:
-            QtWidgets.qApp.restoreOverrideCursor()
+            QtWidgets.QApplication.restoreOverrideCursor()
 
         # Close the copied file (which is not necessarely selected in
         # the tree view because closing an overwritten file can change
diff --git a/vitables/vtgui.py b/vitables/vtgui.py
index 15d7bb8c..cd00dc7a 100644
--- a/vitables/vtgui.py
+++ b/vitables/vtgui.py
@@ -151,8 +151,6 @@ def addComponents(self):
 
         # The signal mapper used to keep the the Window menu updated
         self.window_mapper = QtCore.QSignalMapper(self)
-        self.window_mapper.mapped[QtWidgets.QWidget].connect(
-            self.workspace.setActiveSubWindow)
         self.workspace.installEventFilter(self)
         self.dbs_tree_view.clicked.connect(self.selection_changed)
 
@@ -678,7 +676,7 @@ def closeEvent(self, event):
 
         # Quit
         event.accept()
-        QtWidgets.qApp.quit()
+        QtWidgets.QApplication.quit()
 
     def makeCopy(self):
         """Copy text/leaf depending on which widget has focus.
diff --git a/vitables/vtsplash.py b/vitables/vtsplash.py
index 7f76a11e..0bbcdbdb 100644
--- a/vitables/vtsplash.py
+++ b/vitables/vtsplash.py
@@ -74,7 +74,7 @@ def drawMessage(self, msg):
         :Parameter msg: the message to be displayed
         """
 
-        QtWidgets.qApp.processEvents()
+        QtWidgets.QApplication.processEvents()
         self.msg = msg
         self.showMessage(self.msg)
         time.sleep(0.500)
diff --git a/vitables/vttables/datasheet.py b/vitables/vttables/datasheet.py
index abf6443e..cb83cae1 100644
--- a/vitables/vttables/datasheet.py
+++ b/vitables/vttables/datasheet.py
@@ -110,7 +110,7 @@ def closeEvent(self, event):
         QtWidgets.QMdiSubWindow.closeEvent(self, event)
 
         if not self.vtgui.workspace.subWindowList():
-            self.vtgui.dbs_tree_view.setFocus(True)
+            self.vtgui.dbs_tree_view.setFocus()
 
     def focusInEvent(self, event):
         """Specialised handler for focus events.
@@ -125,7 +125,7 @@ def focusInEvent(self, event):
         # clicked is counter intuitive)
         QtWidgets.QMdiSubWindow.focusInEvent(self, event)
         self.syncTreeView()
-        self.setFocus(True)
+        self.setFocus()
 
     def syncTreeView(self):
         """