diff --git a/cura/Machines/QualityChangesGroup.py b/cura/Machines/QualityChangesGroup.py
index 4881f70839..f798a18e29 100644
--- a/cura/Machines/QualityChangesGroup.py
+++ b/cura/Machines/QualityChangesGroup.py
@@ -1,12 +1,23 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-from .QualityGroup import QualityGroup
+from PyQt5.QtCore import QObject
+from typing import Any, Dict, Optional
 
-class QualityChangesGroup(QualityGroup):
+##  Data struct to group several quality changes instance containers together.
+#
+#   Each group represents one "custom profile" as the user sees it, which
+#   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:
-        super().__init__(name, quality_type, parent)
+        super().__init__(parent)
+        self.name = name
+        self.quality_type = quality_type
         self.intent_category = intent_category
+        self.is_available = False
+        self.metadata_for_global = None  # type: Optional[str]
+        self.metadata_per_extruder = {}  # type: Dict[int, Dict[str, Any]]
 
     def __str__(self) -> str:
-        return "%s[<%s>, available = %s]" % (self.__class__.__name__, self.name, self.is_available)
+        return "{class_name}[{name}, available = {is_available}]".format(class_name = self.__class__.__name__, name = self.name, is_available = self.is_available)