diff --git a/tests/test_pool.py b/tests/test_pool.py
index c80755c63c..1d90854c09 100644
--- a/tests/test_pool.py
+++ b/tests/test_pool.py
@@ -62,7 +62,7 @@ def _callback(pool, result):
 def test_input_cannot_be_submitted_from_worker():
     pool: MultiPool
 
-    def submit_task(_):
+    def submit_task(_) -> Exception | None:
         nonlocal pool
         try:
             pool.submit("this should fail")
diff --git a/unblob/finder.py b/unblob/finder.py
index 207db18812..b602067792 100644
--- a/unblob/finder.py
+++ b/unblob/finder.py
@@ -3,7 +3,7 @@
 The main "entry point" is search_chunks_by_priority.
 """
 from functools import lru_cache
-from typing import List, Optional
+from typing import List
 
 import attr
 from pyperscan import Flag, Pattern, Scan, StreamDatabase
@@ -29,7 +29,7 @@ class HyperscanMatchContext:
 
 def _calculate_chunk(
     handler: Handler, file: File, real_offset, task_result: TaskResult
-) -> Optional[ValidChunk]:
+) -> ValidChunk | None:
     file.seek(real_offset)
     try:
         return handler.calculate_chunk(file, real_offset)
diff --git a/unblob/processing.py b/unblob/processing.py
index 72b500a301..f7eb930cc2 100644
--- a/unblob/processing.py
+++ b/unblob/processing.py
@@ -362,7 +362,7 @@ def _process_directory(self) -> Tuple[Set[Path], Set[Path]]:
     @staticmethod
     def _calculate_multifile(
         dir_handler: DirectoryHandler, path: Path, task_result: TaskResult
-    ) -> Optional[MultiFile]:
+    ) -> MultiFile | None:
         try:
             return dir_handler.calculate_multifile(path)
         except InvalidInputFormat as exc:
diff --git a/unblob/signals.py b/unblob/signals.py
index 76b70a4dbe..2c4837c96d 100644
--- a/unblob/signals.py
+++ b/unblob/signals.py
@@ -1,5 +1,6 @@
 import functools
 import signal
+from typing import Callable
 
 from structlog import get_logger
 
@@ -14,7 +15,7 @@ def __init__(self, signal: str):
 
 def terminate_gracefully(func):
     @functools.wraps(func)
-    def decorator(*args, **kwargs):
+    def decorator(*args, **kwargs) -> Callable | None:
         signals_fired = []
 
         def _handle_signal(signum: int, frame):