diff --git a/cura/CuraPackageManager.py b/cura/CuraPackageManager.py
index 3ef24368fd..e3595ef4bb 100644
--- a/cura/CuraPackageManager.py
+++ b/cura/CuraPackageManager.py
@@ -1,7 +1,7 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-from typing import Any, Dict, List, Tuple, TYPE_CHECKING, Optional, Generator
+from typing import Any, cast, Dict, List, Tuple, TYPE_CHECKING, Optional, Generator
 
 from cura.CuraApplication import CuraApplication #To find some resource types.
 from cura.Settings.GlobalStack import GlobalStack
@@ -30,7 +30,9 @@ class CuraPackageManager(PackageManager):
         """locally installed packages, lazy execution"""
         if self._local_packages is None:
             self._updateLocalPackages()
-        return self._local_packages
+            # _updateLocalPackages always results in a list of packages, not None.
+            # It's guaranteed to be a list now.
+        return cast(List[Dict[str, Any]], self._local_packages)
 
     def initialize(self) -> None:
         self._installation_dirs_dict["materials"] = Resources.getStoragePath(CuraApplication.ResourceTypes.MaterialInstanceContainer)
diff --git a/plugins/Marketplace/PackageList.py b/plugins/Marketplace/PackageList.py
index e41d28721c..9414bb9b28 100644
--- a/plugins/Marketplace/PackageList.py
+++ b/plugins/Marketplace/PackageList.py
@@ -5,7 +5,7 @@ import json
 import os.path
 
 from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, Qt
-from typing import Dict, Optional, Set, TYPE_CHECKING
+from typing import cast, Dict, Optional, Set, TYPE_CHECKING
 
 from UM.i18n import i18nCatalog
 from UM.Qt.ListModel import ListModel
@@ -15,7 +15,7 @@ from UM.Logger import Logger
 from UM import PluginRegistry
 
 from cura.CuraApplication import CuraApplication
-from cura import CuraPackageManager
+from cura.CuraPackageManager import CuraPackageManager
 from cura.UltimakerCloud.UltimakerCloudScope import UltimakerCloudScope  # To make requests to the Ultimaker API with correct authorization.
 
 from .PackageModel import PackageModel
@@ -24,6 +24,7 @@ from .LicenseModel import LicenseModel
 
 if TYPE_CHECKING:
     from PyQt5.QtCore import QObject
+    from PyQt5.QtNetwork import QNetworkReply
 
 catalog = i18nCatalog("cura")
 
@@ -37,7 +38,7 @@ class PackageList(ListModel):
 
     def __init__(self, parent: Optional["QObject"] = None) -> None:
         super().__init__(parent)
-        self._manager: CuraPackageManager = CuraApplication.getInstance().getPackageManager()
+        self._manager: CuraPackageManager = cast(CuraPackageManager, CuraApplication.getInstance().getPackageManager())
         self._plugin_registry: PluginRegistry = CuraApplication.getInstance().getPluginRegistry()
         self._account = CuraApplication.getInstance().getCuraAPI().account
         self._error_message = ""
diff --git a/plugins/Marketplace/PackageModel.py b/plugins/Marketplace/PackageModel.py
index 92daf310a3..f7682340c9 100644
--- a/plugins/Marketplace/PackageModel.py
+++ b/plugins/Marketplace/PackageModel.py
@@ -71,11 +71,13 @@ class PackageModel(QObject):
         self.sdk_version = package_data.get("sdk_version_semver", "")
         # Note that there's a lot more info in the package_data than just these specified here.
 
-    def __eq__(self, other: Union[str, "PackageModel"]):
+    def __eq__(self, other: object):
         if isinstance(other, PackageModel):
             return other == self
-        else:
+        elif isinstance(other, str):
             return other == self._package_id
+        else:
+            return False
 
     def __repr__(self):
         return f"<{self._package_id} : {self._package_version} : {self._section_title}>"