diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9882717..86001fd 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,15 +1,15 @@
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v5.0.0
+    rev: v6.0.0
     hooks:
       - id: check-yaml
       - id: end-of-file-fixer
       - id: trailing-whitespace
-  - repo: https://github.com/psf/black
-    rev: 25.1.0
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 26.1.0
     hooks:
       - id: black
   - repo: https://github.com/kynan/nbstripout
-    rev: 0.8.1
+    rev: 0.9.1
     hooks:
       - id: nbstripout
diff --git a/tools/__init__.py b/tools/__init__.py
index 54a693e..578db2a 100644
--- a/tools/__init__.py
+++ b/tools/__init__.py
@@ -4,6 +4,7 @@
 # @Last Modified by:   Kelvin
 # @Last Modified time: 2022-07-18 11:55:02
 """tools package"""
+
 import matplotlib
 
 FONTTYPE = 42
diff --git a/tools/sc/_sc.py b/tools/sc/_sc.py
index dff20bc..46e2997 100644
--- a/tools/sc/_sc.py
+++ b/tools/sc/_sc.py
@@ -4,6 +4,7 @@
 # @Last Modified by:   Kelvin
 # @Last Modified time: 2022-11-17 16:09:57
 """Miscellaneous single-cell functions."""
+
 import functools
 import math
 import scipy.sparse
diff --git a/tools/tools/__init__.py b/tools/tools/__init__.py
index cb264e4..e494cdf 100644
--- a/tools/tools/__init__.py
+++ b/tools/tools/__init__.py
@@ -4,6 +4,7 @@
 # @Last Modified by:   Kelvin
 # @Last Modified time: 2022-08-16 14:19:43
 """tools module."""
+
 from ._tools import (
     alpha_code,
     cmp,
diff --git a/tools/tools/_tools.py b/tools/tools/_tools.py
index 3ed9cde..621147f 100644
--- a/tools/tools/_tools.py
+++ b/tools/tools/_tools.py
@@ -4,6 +4,7 @@
 # @Last Modified by:   Kelvin
 # @Last Modified time: 2022-08-16 14:19:25
 """Miscellaneous functions."""
+
 import numpy as np
 
 import matplotlib.pyplot as plt