diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 03d3a07c9dcc91c1b394a4a6bdef70e6706c7ba4..5aef07dd643178d59e80f9bbad77b5960b16a56f 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -11,7 +11,7 @@ repos:
     hooks:
     -   id: trailing-whitespace
 -   repo: https://github.com/psf/black
-    rev: 22.12.0
+    rev: 23.1.0
     hooks:
     -   id: black
 -   repo: https://github.com/cheshirekow/cmake-format-precommit
diff --git a/unittest/python/test_eigen_ref.py b/unittest/python/test_eigen_ref.py
index 8d466f1d85d2d32e9a3cf9dc80aecd19a15303f1..6c934af410f51a71ee14f69f15d8bbeaef54061e 100644
--- a/unittest/python/test_eigen_ref.py
+++ b/unittest/python/test_eigen_ref.py
@@ -15,7 +15,6 @@ from eigen_ref import (
 
 
 def test_fill_print(mat):
-
     print("print matrix:")
     printMatrix(mat)
     print("calling fill():")
diff --git a/unittest/python/test_return_by_ref.py b/unittest/python/test_return_by_ref.py
index dff108ce9793c7b127a60f067ec4ae2b187484df..e43735da9524f7beed42d2da3e4fec8fc9c8a59a 100644
--- a/unittest/python/test_return_by_ref.py
+++ b/unittest/python/test_return_by_ref.py
@@ -4,7 +4,6 @@ import numpy as np
 
 
 def test_shared(mat):
-
     m_ref = mat.ref()
     m_ref.fill(0)
     m_copy = mat.copy()
@@ -26,7 +25,6 @@ def test_shared(mat):
 
 
 def test_not_shared(mat):
-
     m_ref = mat.ref()
     m_ref.fill(100.0)
     m_copy = mat.copy()