diff --git a/mypy-requirements.txt b/mypy-requirements.txt
index 41c0195c..7453ac77 100644
--- a/mypy-requirements.txt
+++ b/mypy-requirements.txt
@@ -1,5 +1,5 @@
 mypy[mypyc]==2.0.0  # update pyproject.toml as well
-black>=23.12,<26.4
+black>=26.5.0,<26.6
 types-requests
 types-dataclasses
 objgraph
diff --git a/pyproject.toml b/pyproject.toml
index 388fc63d..5bd2c373 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ requires = [
     "setuptools>=50",  # 50 is to match mypyc's minimum
     "setuptools_scm[toml]>=8.0.4,<11",
     'mypy[mypyc]==2.0.0',  # update mypy-requirements as well
-    "black>=19.10b0,<26.4",
+    "black>=26.5.0,<26.6",
     "types-requests",
     "types-dataclasses",
     "ruamel.yaml>= 0.17.6, < 0.20",
diff --git a/requirements.txt b/requirements.txt
index 07ddcf5b..89b2369d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,6 +3,6 @@ ruamel.yaml >= 0.17.6, < 0.20
 rdflib>= 4.2.2, < 8.0.0
 mistune>=3,<3.3
 CacheControl[filecache]>= 0.13.1, < 0.15
-black>=19.10b0,<26.4
+black>=26.5.0,<26.6
 mypy_extensions
 rich-argparse