diff --git a/pyqtgraph/Qt.py b/pyqtgraph/Qt.py
index 83654c93..23e75570 100644
--- a/pyqtgraph/Qt.py
+++ b/pyqtgraph/Qt.py
@@ -320,14 +320,6 @@ if QT_LIB in [PYQT5, PYQT6, PYSIDE2, PYSIDE6]:
         self.setTransform(tr)
     QtWidgets.QGraphicsItem.translate = translate
 
-    def setMargin(self, i):
-        self.setContentsMargins(i, i, i, i)
-    QtWidgets.QGridLayout.setMargin = setMargin
-
-    def setResizeMode(self, *args):
-        self.setSectionResizeMode(*args)
-    QtWidgets.QHeaderView.setResizeMode = setResizeMode
-
     
     QtGui.QApplication = QtWidgets.QApplication
     QtGui.QGraphicsScene = QtWidgets.QGraphicsScene
diff --git a/pyqtgraph/flowchart/Flowchart.py b/pyqtgraph/flowchart/Flowchart.py
index c904e710..49436e4e 100644
--- a/pyqtgraph/flowchart/Flowchart.py
+++ b/pyqtgraph/flowchart/Flowchart.py
@@ -616,10 +616,7 @@ class FlowchartCtrlWidget(QtGui.QWidget):
         self.cwWin.resize(1000,800)
         
         h = self.ui.ctrlList.header()
-        if QT_LIB in ['PyQt4', 'PySide']:
-            h.setResizeMode(0, h.Stretch)
-        else:
-            h.setSectionResizeMode(0, h.Stretch)
+        h.setSectionResizeMode(0, h.ResizeMode.Stretch)
         
         self.ui.ctrlList.itemChanged.connect(self.itemChanged)
         self.ui.loadBtn.clicked.connect(self.loadClicked)
diff --git a/pyqtgraph/parametertree/ParameterTree.py b/pyqtgraph/parametertree/ParameterTree.py
index 8c89d37e..203c6513 100644
--- a/pyqtgraph/parametertree/ParameterTree.py
+++ b/pyqtgraph/parametertree/ParameterTree.py
@@ -1,4 +1,4 @@
-from ..Qt import QtCore, QtGui
+from ..Qt import QtCore, QtWidgets
 from ..widgets.TreeWidget import TreeWidget
 import os, weakref, re
 from .ParameterItem import ParameterItem
@@ -25,7 +25,7 @@ class ParameterTree(TreeWidget):
         self.setHeaderLabels(["Parameter", "Value"])
         self.setAlternatingRowColors(True)
         self.paramSet = None
-        self.header().setResizeMode(QtGui.QHeaderView.ResizeToContents)
+        self.header().setSectionResizeMode(QtWidgets.QHeaderView.ResizeMode.ResizeToContents)
         self.setHeaderHidden(not showHeader)
         self.itemChanged.connect(self.itemChangedEvent)
         self.itemExpanded.connect(self.itemExpandedEvent)