diff --git a/pyomo/contrib/viewer/model_browser.py b/pyomo/contrib/viewer/model_browser.py
index 064e03c196f..8379518a4cf 100644
--- a/pyomo/contrib/viewer/model_browser.py
+++ b/pyomo/contrib/viewer/model_browser.py
@@ -102,17 +102,16 @@ def setModelData(self, editor, model, index):
 
 
 class ModelBrowser(_ModelBrowser, _ModelBrowserUI):
-    def __init__(self, ui_data, parent=None, standard="Var"):
+    def __init__(self, ui_data, standard="Var"):
         """
-        Create a dock widdget with a QTreeView of a Pyomo model.
+        Create a dock widget with a QTreeView of a Pyomo model.
 
         Args:
-            parent: parent widget
             ui_data: Contains model and ui information
             standard: A standard setup for different types of model components
                 {"Var", "Constraint", "Param", "Expression"}
         """
-        super().__init__(parent=parent)
+        super().__init__()
         self.setupUi(self)
         # The default int and double spin boxes are not good for this
         # application.  So just use regular line edits.
diff --git a/pyomo/contrib/viewer/model_select.py b/pyomo/contrib/viewer/model_select.py
index 2b81cda6665..3c6c4ccdf17 100644
--- a/pyomo/contrib/viewer/model_select.py
+++ b/pyomo/contrib/viewer/model_select.py
@@ -49,8 +49,8 @@ class _ModelSelect(object):
 
 
 class ModelSelect(_ModelSelect, _ModelSelectUI):
-    def __init__(self, ui_data, parent=None):
-        super().__init__(parent=parent)
+    def __init__(self, parent, ui_data):
+        super().__init__(parent)
         self.setupUi(self)
         self.ui_data = ui_data
         self.closeButton.clicked.connect(self.close)
diff --git a/pyomo/contrib/viewer/pyomo_viewer.py b/pyomo/contrib/viewer/pyomo_viewer.py
index f11f129cacd..a8fec745af4 100644
--- a/pyomo/contrib/viewer/pyomo_viewer.py
+++ b/pyomo/contrib/viewer/pyomo_viewer.py
@@ -26,7 +26,7 @@
 from pyomo.scripting.pyomo_parser import add_subparser
 import pyomo.contrib.viewer.qt as myqt
 
-qtconsole_app, qtconsole_available = attempt_import('qtconsole.qtconsoleapp')
+qtconsole_app, qtconsole_available = attempt_import("qtconsole.qtconsoleapp")
 
 
 class QtApp(
@@ -97,13 +97,9 @@ def kernel_pyomo_init(self, kc):
     def init_qt_elements(self):
         super().init_qt_elements()
         self.kernel_pyomo_init(self.widget.kernel_client)
-        self.run_script_act = myqt.QtWidgets.QAction("&Run Script...", self.window)
-        self.show_ui_act = myqt.QtWidgets.QAction(
-            "&Show Pyomo Model Viewer", self.window
-        )
-        self.hide_ui_act = myqt.QtWidgets.QAction(
-            "&Hide Pyomo Model Viewer", self.window
-        )
+        self.run_script_act = myqt.QAction("&Run Script...", self.window)
+        self.show_ui_act = myqt.QAction("&Show Pyomo Model Viewer", self.window)
+        self.hide_ui_act = myqt.QAction("&Hide Pyomo Model Viewer", self.window)
         self.window.file_menu.addSeparator()
         self.window.file_menu.addAction(self.run_script_act)
         self.window.view_menu.addSeparator()
@@ -125,7 +121,7 @@ def main(*args):
         errors = list(myqt.import_errors)
         if not qtconsole_available:
             errors.append(qtconsole_app._moduleunavailable_message())
-        print("qt not available\n    " + '\n    '.join(errors))
+        print("qt not available\n    " + "\n    ".join(errors))
         return
     QtApp.launch_instance()
 
diff --git a/pyomo/contrib/viewer/residual_table.py b/pyomo/contrib/viewer/residual_table.py
index 17eca6b3057..46a86adbce6 100644
--- a/pyomo/contrib/viewer/residual_table.py
+++ b/pyomo/contrib/viewer/residual_table.py
@@ -50,8 +50,8 @@ class _ResidualTable(object):
 
 
 class ResidualTable(_ResidualTable, _ResidualTableUI):
-    def __init__(self, ui_data, parent=None):
-        super().__init__(parent=parent)
+    def __init__(self, ui_data):
+        super().__init__()
         self.setupUi(self)
         self.ui_data = ui_data
         datmodel = ResidualDataModel(parent=self, ui_data=ui_data)