diff --git a/plugins/FirmwareUpdateChecker/FirmwareUpdateCheckerJob.py b/plugins/FirmwareUpdateChecker/FirmwareUpdateCheckerJob.py
index d726cc04a9..8d08cde37b 100644
--- a/plugins/FirmwareUpdateChecker/FirmwareUpdateCheckerJob.py
+++ b/plugins/FirmwareUpdateChecker/FirmwareUpdateCheckerJob.py
@@ -12,7 +12,7 @@ from urllib.error import URLError
 from typing import Dict
 import ssl
 
-import certifi
+import certifi  # type: ignore
 
 from .FirmwareUpdateCheckerLookup import FirmwareUpdateCheckerLookup, getSettingsKeyForMachine
 from .FirmwareUpdateCheckerMessage import FirmwareUpdateCheckerMessage
diff --git a/plugins/GCodeReader/FlavorParser.py b/plugins/GCodeReader/FlavorParser.py
index bb99aa59ec..8d35bd3345 100644
--- a/plugins/GCodeReader/FlavorParser.py
+++ b/plugins/GCodeReader/FlavorParser.py
@@ -24,7 +24,7 @@ from cura.Settings.ExtruderManager import ExtruderManager
 
 catalog = i18nCatalog("cura")
 
-PositionOptional = NamedTuple("Position", [("x", Optional[float]), ("y", Optional[float]), ("z", Optional[float]), ("f", Optional[float]), ("e", Optional[float])])
+PositionOptional = NamedTuple("PositionOptional", [("x", Optional[float]), ("y", Optional[float]), ("z", Optional[float]), ("f", Optional[float]), ("e", Optional[float])])
 Position = NamedTuple("Position", [("x", float), ("y", float), ("z", float), ("f", float), ("e", List[float])])
 
 
diff --git a/plugins/PostProcessingPlugin/PostProcessingPlugin.py b/plugins/PostProcessingPlugin/PostProcessingPlugin.py
index 8968e2c547..755d815d0a 100644
--- a/plugins/PostProcessingPlugin/PostProcessingPlugin.py
+++ b/plugins/PostProcessingPlugin/PostProcessingPlugin.py
@@ -193,6 +193,8 @@ class PostProcessingPlugin(QObject, Extension):
 
                     spec = importlib.util.spec_from_file_location(__name__ + "." + script_name,
                                                                   file_path)
+                    if spec is None:
+                        continue
                     loaded_script = importlib.util.module_from_spec(spec)
                     if spec.loader is None:
                         continue