diff --git a/pyproject.toml b/pyproject.toml
index 1d46bfcb..17db9b05 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,9 +68,9 @@ dev-flake8 = [
   "pydoclint == 0.8.3",
   "pydocstyle == 6.3.0",
 ]
-dev-formatting = ["black == 25.11.0", "isort == 8.0.1"]
+dev-formatting = ["black == 26.3.1", "isort == 8.0.1"]
 dev-mkdocs = [
-  "black == 25.11.0",
+  "black == 26.3.1",
   "Markdown == 3.10.2",
   "mike == 2.1.4",
   "mkdocs-gen-files == 0.6.1",
diff --git a/src/frequenz/client/dispatch/_internal_types.py b/src/frequenz/client/dispatch/_internal_types.py
index c2d8f1d0..6bca9824 100644
--- a/src/frequenz/client/dispatch/_internal_types.py
+++ b/src/frequenz/client/dispatch/_internal_types.py
@@ -3,7 +3,6 @@
 
 """Type wrappers for the generated protobuf messages."""
 
-
 from dataclasses import dataclass
 from datetime import datetime, timedelta
 from typing import Any, Literal
diff --git a/src/frequenz/client/dispatch/test/_service.py b/src/frequenz/client/dispatch/test/_service.py
index 3d4505ed..6a57c9fc 100644
--- a/src/frequenz/client/dispatch/test/_service.py
+++ b/src/frequenz/client/dispatch/test/_service.py
@@ -5,6 +5,7 @@
 
 Useful for testing.
 """
+
 import logging
 from dataclasses import dataclass, replace
 from datetime import datetime, timezone
diff --git a/src/frequenz/client/dispatch/types.py b/src/frequenz/client/dispatch/types.py
index 8c61b30a..d06586ce 100644
--- a/src/frequenz/client/dispatch/types.py
+++ b/src/frequenz/client/dispatch/types.py
@@ -3,7 +3,6 @@
 
 """Type wrappers for the generated protobuf messages."""
 
-
 from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
 from enum import Enum