diff --git a/pypiserver/backend.py b/pypiserver/backend.py
index 4119f8c..887dabd 100644
--- a/pypiserver/backend.py
+++ b/pypiserver/backend.py
@@ -204,7 +204,7 @@ def write_file(fh: t.BinaryIO, destination: PathLike) -> None:
     """write a byte stream into a destination file. Writes are chunked to reduce
     the memory footprint
     """
-    chunk_size = 2 ** 20  # 1 MB
+    chunk_size = 2**20  # 1 MB
     offset = fh.tell()
     try:
         with open(destination, "wb") as dest:
@@ -259,7 +259,7 @@ def digest_file(file_path: PathLike, hash_algo: str) -> str:
 
     From http://stackoverflow.com/a/21565932/548792
     """
-    blocksize = 2 ** 16
+    blocksize = 2**16
     digester = hashlib.new(hash_algo)
     with open(file_path, "rb") as f:
         for block in iter(lambda: f.read(blocksize), b""):
diff --git a/tests/test_server.py b/tests/test_server.py
index cef95c8..18119ca 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -57,7 +57,7 @@ def run_server(root, authed=False, other_cli=""):
         f"run -vvv --overwrite -i 127.0.0.1 "
         f"-p {port} {pswd_opts} {other_cli} {root}"
     )
-    proc = Popen(cmd.split(), bufsize=2 ** 16)
+    proc = Popen(cmd.split(), bufsize=2**16)
     srv = Srv(port, root)
     try:
         wait_until_ready(srv)