diff --git a/cura/Settings/AbstractMachine.py b/cura/Settings/AbstractMachine.py
index 477edc0a0e..d3cae76ccb 100644
--- a/cura/Settings/AbstractMachine.py
+++ b/cura/Settings/AbstractMachine.py
@@ -11,7 +11,7 @@ from UM.Settings.ContainerRegistry import ContainerRegistry
 class AbstractMachine(GlobalStack):
     """ Represents a group of machines of the same type. This allows the user to select settings before selecting a printer. """
 
-    def __init__(self, container_id: str):
+    def __init__(self, container_id: str) -> None:
         super().__init__(container_id)
         self.setMetaDataEntry("type", "abstract_machine")
 
diff --git a/cura/Settings/CuraStackBuilder.py b/cura/Settings/CuraStackBuilder.py
index 98ad3075b7..6a9ae728b7 100644
--- a/cura/Settings/CuraStackBuilder.py
+++ b/cura/Settings/CuraStackBuilder.py
@@ -210,7 +210,7 @@ class CuraStackBuilder:
                             stack: GlobalStack,
                             variant_container: "InstanceContainer",
                             material_container: "InstanceContainer",
-                            quality_container: "InstanceContainer"):
+                            quality_container: "InstanceContainer") -> None:
         from cura.CuraApplication import CuraApplication
         application = CuraApplication.getInstance()
 
@@ -268,7 +268,7 @@ class CuraStackBuilder:
         return definition_changes_container
 
     @classmethod
-    def createAbstractMachine(cls, definition_id) -> Optional[AbstractMachine]:
+    def createAbstractMachine(cls, definition_id: str) -> Optional[AbstractMachine]:
         """Create a new instance of an abstract machine.
 
         :param definition_id: The ID of the machine definition to use.