diff --git a/sphinx/testing/fixtures.py b/sphinx/testing/fixtures.py
index 899fea6b613..03e38e85e86 100644
--- a/sphinx/testing/fixtures.py
+++ b/sphinx/testing/fixtures.py
@@ -239,7 +239,7 @@ def if_graphviz_found(app: SphinxTestApp) -> None:  # NoQA: PT004
 
 
 @pytest.fixture(scope='session')
-def sphinx_test_tempdir(tmp_path_factory: Any) -> Path:
+def sphinx_test_tempdir(tmp_path_factory: pytest.TempPathFactory) -> Path:
     """Temporary directory."""
     return tmp_path_factory.getbasetemp()
 
diff --git a/sphinx/testing/path.py b/sphinx/testing/path.py
index 3a9ee8ddb20..49f0ffa6005 100644
--- a/sphinx/testing/path.py
+++ b/sphinx/testing/path.py
@@ -178,7 +178,7 @@ def read_bytes(self) -> builtins.bytes:
         with open(self, mode='rb') as f:
             return f.read()
 
-    def write_bytes(self, bytes: str, append: bool = False) -> None:
+    def write_bytes(self, bytes: bytes, append: bool = False) -> None:
         """
         Writes the given `bytes` to the file.
 
diff --git a/sphinx/util/parallel.py b/sphinx/util/parallel.py
index 32912e014d7..f17ef71294b 100644
--- a/sphinx/util/parallel.py
+++ b/sphinx/util/parallel.py
@@ -23,7 +23,7 @@
 logger = logging.getLogger(__name__)
 
 # our parallel functionality only works for the forking Process
-parallel_available = multiprocessing and os.name == 'posix'
+parallel_available = HAS_MULTIPROCESSING and os.name == 'posix'
 
 
 class SerialTasks: