diff --git a/plugins/DigitalLibrary/src/DFFileUploader.py b/plugins/DigitalLibrary/src/DFFileUploader.py
index 6cad7828e2..23a4620bcf 100644
--- a/plugins/DigitalLibrary/src/DFFileUploader.py
+++ b/plugins/DigitalLibrary/src/DFFileUploader.py
@@ -39,8 +39,8 @@ class DFFileUploader:
         :param on_error: The method to be called when an error occurs.
         """
 
-        self._http = http  # type: HttpRequestManager
-        self._df_file = df_file  # type: Union[DFLibraryFileUploadResponse, DFPrintJobUploadResponse]
+        self._http: HttpRequestManager = http
+        self._df_file: Union[DFLibraryFileUploadResponse, DFPrintJobUploadResponse] = df_file
         self._file_name = ""
         if isinstance(self._df_file, DFLibraryFileUploadResponse):
             self._file_name = self._df_file.file_name
@@ -51,7 +51,7 @@ class DFFileUploader:
                 self._file_name = ""
         else:
             raise TypeError("Incorrect input type")
-        self._data = data  # type: bytes
+        self._data: bytes = data
 
         self._on_finished = on_finished
         self._on_success = on_success
diff --git a/plugins/DigitalLibrary/src/DigitalFactoryApiClient.py b/plugins/DigitalLibrary/src/DigitalFactoryApiClient.py
index 3456638ba6..de09ea2a09 100644
--- a/plugins/DigitalLibrary/src/DigitalFactoryApiClient.py
+++ b/plugins/DigitalLibrary/src/DigitalFactoryApiClient.py
@@ -40,7 +40,7 @@ class DigitalFactoryApiClient:
     DEFAULT_REQUEST_TIMEOUT = 10  # seconds
 
     # In order to avoid garbage collection we keep the callbacks in this list.
-    _anti_gc_callbacks = []  # type: List[Callable[[Any], None]]
+    _anti_gc_callbacks: List[Callable[[Any], None]] = []
 
     def __init__(self, application: CuraApplication, on_error: Callable[[List[CloudError]], None], projects_limit_per_page: Optional[int] = None) -> None:
         """Initializes a new digital factory API client.
@@ -54,7 +54,7 @@ class DigitalFactoryApiClient:
         self._scope = JsonDecoratorScope(UltimakerCloudScope(application))
         self._http = HttpRequestManager.getInstance()
         self._on_error = on_error
-        self._file_uploader = None  # type: Optional[DFFileUploader]
+        self._file_uploader: Optional[DFFileUploader] = None
         self._library_max_private_projects: Optional[int] = None
 
         self._projects_pagination_mgr = PaginationManager(limit = projects_limit_per_page) if projects_limit_per_page else None  # type: Optional[PaginationManager]