diff --git a/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py b/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
index 3ade02120d..8fe9b26517 100644
--- a/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
+++ b/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
@@ -7,10 +7,12 @@ import cura.CuraApplication  # Imported this way to prevent circular references.
 from cura.Machines.ContainerTree import ContainerTree
 from cura.Machines.Models.QualityProfilesDropDownMenuModel import QualityProfilesDropDownMenuModel
 
+
 ##  This model is used for the custom profile items in the profile drop down
 #   menu.
 class CustomQualityProfilesDropDownMenuModel(QualityProfilesDropDownMenuModel):
-    def _update(self):
+
+    def _update(self) -> None:
         Logger.log("d", "Updating {model_class_name}.".format(model_class_name = self.__class__.__name__))
 
         active_global_stack = cura.CuraApplication.CuraApplication.getInstance().getMachineManager().activeMachine
@@ -31,4 +33,4 @@ class CustomQualityProfilesDropDownMenuModel(QualityProfilesDropDownMenuModel):
 
             item_list.append(item)
 
-        self.setItems(item_list)
\ No newline at end of file
+        self.setItems(item_list)
diff --git a/cura/Machines/QualityChangesGroup.py b/cura/Machines/QualityChangesGroup.py
index 65ebb71f4c..f2bb0f737d 100644
--- a/cura/Machines/QualityChangesGroup.py
+++ b/cura/Machines/QualityChangesGroup.py
@@ -10,7 +10,8 @@ from typing import Any, Dict, Optional
 #   contains an instance container for the global stack and one instance
 #   container per extruder.
 class QualityChangesGroup(QObject):
-    def __init__(self, name: str, quality_type: str, intent_category: str, parent = None) -> None:
+
+    def __init__(self, name: str, quality_type: str, intent_category: str, parent: Optional["QObject"] = None) -> None:
         super().__init__(parent)
         self.name = name
         self.quality_type = quality_type
diff --git a/resources/qml/PrintSetupSelector/Custom/QualitiesWithIntentMenu.qml b/resources/qml/PrintSetupSelector/Custom/QualitiesWithIntentMenu.qml
index cff4e3e7a6..2d5f880344 100644
--- a/resources/qml/PrintSetupSelector/Custom/QualitiesWithIntentMenu.qml
+++ b/resources/qml/PrintSetupSelector/Custom/QualitiesWithIntentMenu.qml
@@ -103,7 +103,7 @@ Popup
                             text: model.name + " - " + model.layer_height + " mm"
                             checked:
                             {
-                                if(Cura.MachineManager.hasCustomQuality)
+                                if (Cura.MachineManager.hasCustomQuality)
                                 {
                                     // When user created profile is active, no quality tickbox should be active.
                                     return false;