diff --git a/cwltool/load_tool.py b/cwltool/load_tool.py
index 4d7f3a930..f7f4936cd 100644
--- a/cwltool/load_tool.py
+++ b/cwltool/load_tool.py
@@ -142,7 +142,7 @@ def fetch_document(
 
 
 def _convert_stdstreams_to_files(
-    workflowobj: Union[CWLObjectType, MutableSequence[Union[CWLObjectType, str, int]], str]
+    workflowobj: Union[CWLObjectType, MutableSequence[Union[CWLObjectType, str, int]], str],
 ) -> None:
     if isinstance(workflowobj, MutableMapping):
         if workflowobj.get("class") == "CommandLineTool":
@@ -219,7 +219,7 @@ def _convert_stdstreams_to_files(
 
 
 def _add_blank_ids(
-    workflowobj: Union[CWLObjectType, MutableSequence[Union[CWLObjectType, str]]]
+    workflowobj: Union[CWLObjectType, MutableSequence[Union[CWLObjectType, str]]],
 ) -> None:
     if isinstance(workflowobj, MutableMapping):
         if (
@@ -247,7 +247,7 @@ def _add_blank_ids(
 
 
 def _fast_parser_convert_stdstreams_to_files(
-    processobj: Union[cwl_v1_2.Process, MutableSequence[cwl_v1_2.Process]]
+    processobj: Union[cwl_v1_2.Process, MutableSequence[cwl_v1_2.Process]],
 ) -> None:
     if isinstance(processobj, cwl_v1_2.CommandLineTool):
         cwl_v1_2_utils.convert_stdstreams_to_files(processobj)
diff --git a/cwltool/process.py b/cwltool/process.py
index 9f985a5d5..5271e4643 100644
--- a/cwltool/process.py
+++ b/cwltool/process.py
@@ -305,7 +305,7 @@ def relocateOutputs(
         return outputObj
 
     def _collectDirEntries(
-        obj: Union[CWLObjectType, MutableSequence[CWLObjectType], None]
+        obj: Union[CWLObjectType, MutableSequence[CWLObjectType], None],
     ) -> Iterator[CWLObjectType]:
         if isinstance(obj, dict):
             if obj.get("class") in ("File", "Directory"):
diff --git a/cwltool/utils.py b/cwltool/utils.py
index 2c7f6ba12..c37dbe8e7 100644
--- a/cwltool/utils.py
+++ b/cwltool/utils.py
@@ -398,7 +398,7 @@ def normalizeFilesDirs(
             MutableMapping[str, Any],
             DirectoryType,
         ]
-    ]
+    ],
 ) -> None:
     def addLocation(d: dict[str, Any]) -> None:
         if "location" not in d:
diff --git a/lint-requirements.txt b/lint-requirements.txt
index abb223c85..a2c6768cf 100644
--- a/lint-requirements.txt
+++ b/lint-requirements.txt
@@ -1,3 +1,3 @@
 flake8-bugbear<24.13
-black==24.*
+black==25.*
 codespell