diff --git a/pyproject.toml b/pyproject.toml
index 187b99a2..b05f22aa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,8 +19,7 @@ test = [
     "pytest>=8.4.1",
 ]
 dev = [
-    # black >= 26 requires a reformat
-    "black>=24.3.0,<26.0.0",
+    "black>=24.3.0,<27.0.0",
     "ruff>=0.3.0",
 ]
 
diff --git a/src/s3_encryption/__init__.py b/src/s3_encryption/__init__.py
index adfb6886..46cdbdd1 100644
--- a/src/s3_encryption/__init__.py
+++ b/src/s3_encryption/__init__.py
@@ -1,6 +1,7 @@
 # Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 """Top-level S3 Encryption Client v3 for Python package."""
+
 import io
 
 from attrs import define, field
diff --git a/src/s3_encryption/materials/encrypted_data_key.py b/src/s3_encryption/materials/encrypted_data_key.py
index 28401b40..b2c2359a 100644
--- a/src/s3_encryption/materials/encrypted_data_key.py
+++ b/src/s3_encryption/materials/encrypted_data_key.py
@@ -5,6 +5,7 @@
 This module provides the EncryptedDataKey class which represents an encrypted
 data key used in the S3 encryption process.
 """
+
 from attrs import define
 
 
diff --git a/src/s3_encryption/materials/materials.py b/src/s3_encryption/materials/materials.py
index 9f72ab91..3966e17c 100644
--- a/src/s3_encryption/materials/materials.py
+++ b/src/s3_encryption/materials/materials.py
@@ -6,6 +6,7 @@
 which contain the cryptographic materials needed for S3 object encryption
 and decryption operations.
 """
+
 from typing import Any
 
 from attrs import define, field
diff --git a/src/s3_encryption/metadata.py b/src/s3_encryption/metadata.py
index b4378990..f42feadb 100644
--- a/src/s3_encryption/metadata.py
+++ b/src/s3_encryption/metadata.py
@@ -5,6 +5,7 @@
 This module provides classes and utilities for managing encryption metadata
 for S3 objects, including serialization and deserialization of metadata.
 """
+
 import json
 from typing import Any
 
diff --git a/src/s3_encryption/pipelines.py b/src/s3_encryption/pipelines.py
index 6046fb3a..37093803 100644
--- a/src/s3_encryption/pipelines.py
+++ b/src/s3_encryption/pipelines.py
@@ -5,6 +5,7 @@
 This module provides pipelines for encrypting objects before they are put into S3
 and decrypting objects after they are retrieved from S3.
 """
+
 import base64
 import os