diff --git a/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py b/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
index dcade8cb0d..ea1746acc8 100644
--- a/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
+++ b/cura/Machines/Models/CustomQualityProfilesDropDownMenuModel.py
@@ -1,9 +1,11 @@
-# Copyright (c) 2018 Ultimaker B.V.
+# Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
 from UM.Logger import Logger
 
+import cura.CuraApplication  # Imported this way to prevent circular references.
 from cura.Machines.Models.QualityProfilesDropDownMenuModel import QualityProfilesDropDownMenuModel
+from cura.Machines.QualityManager import QualityManager
 
 
 #
@@ -14,13 +16,13 @@ class CustomQualityProfilesDropDownMenuModel(QualityProfilesDropDownMenuModel):
     def _update(self):
         Logger.log("d", "Updating {model_class_name}.".format(model_class_name = self.__class__.__name__))
 
-        active_global_stack = self._machine_manager.activeMachine
+        active_global_stack = cura.CuraApplication.CuraApplication.getInstance().getMachineManager().activeMachine
         if active_global_stack is None:
             self.setItems([])
             Logger.log("d", "No active GlobalStack, set %s as empty.", self.__class__.__name__)
             return
 
-        quality_changes_group_dict = self._quality_manager.getQualityChangesGroups(active_global_stack)
+        quality_changes_group_dict = QualityManager.getInstance().getQualityChangesGroups(active_global_stack)
 
         item_list = []
         for key in sorted(quality_changes_group_dict, key = lambda name: name.upper()):
diff --git a/cura/Machines/Models/QualityProfilesDropDownMenuModel.py b/cura/Machines/Models/QualityProfilesDropDownMenuModel.py
index b806ce8c1a..8d6c024e8c 100644
--- a/cura/Machines/Models/QualityProfilesDropDownMenuModel.py
+++ b/cura/Machines/Models/QualityProfilesDropDownMenuModel.py
@@ -7,8 +7,8 @@ from UM.Logger import Logger
 from UM.Qt.ListModel import ListModel
 from UM.Settings.SettingFunction import SettingFunction
 
-from cura.CuraApplication import CuraApplication
-from cura.Machines.QualityManager import QualityGroup
+import cura.CuraApplication  # Imported this way to prevent circular dependencies.
+from cura.Machines.QualityManager import QualityGroup, QualityManager
 
 
 #
@@ -36,7 +36,7 @@ class QualityProfilesDropDownMenuModel(ListModel):
         self.addRoleName(self.QualityChangesGroupRole, "quality_changes_group")
         self.addRoleName(self.IsExperimentalRole, "is_experimental")
 
-        application = CuraApplication.getInstance()
+        application = cura.CuraApplication.CuraApplication.getInstance()
         machine_manager = application.getMachineManager()
 
         application.globalContainerStackChanged.connect(self._onChange)
@@ -58,19 +58,19 @@ class QualityProfilesDropDownMenuModel(ListModel):
     def _update(self):
         Logger.log("d", "Updating {model_class_name}.".format(model_class_name = self.__class__.__name__))
 
-        global_stack = CuraApplication.getInstance().getGlobalContainerStack()
+        global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
         if global_stack is None:
             self.setItems([])
             Logger.log("d", "No active GlobalStack, set quality profile model as empty.")
             return
 
         # Check for material compatibility
-        if not CuraApplication.getInstance().getMachineManager().activeMaterialsCompatible():
+        if not cura.CuraApplication.CuraApplication.getInstance().getMachineManager().activeMaterialsCompatible():
             Logger.log("d", "No active material compatibility, set quality profile model as empty.")
             self.setItems([])
             return
 
-        quality_group_dict = self._quality_manager.getQualityGroups(global_stack)
+        quality_group_dict = QualityManager.getInstance().getQualityGroups(global_stack)
 
         item_list = []
         for key in sorted(quality_group_dict):
@@ -94,7 +94,7 @@ class QualityProfilesDropDownMenuModel(ListModel):
         self.setItems(item_list)
 
     def _fetchLayerHeight(self, quality_group: "QualityGroup") -> float:
-        global_stack = CuraApplication.getInstance().getMachineManager().activeMachine
+        global_stack = cura.CuraApplication.CuraApplication.getInstance().getMachineManager().activeMachine
         if not self._layer_height_unit:
             unit = global_stack.definition.getProperty("layer_height", "unit")
             if not unit: