diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 21666d1..8e0af5f 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -24,7 +24,7 @@ repos:
         exclude: ^pyabc2/sources/_lzstring.py
 
   - repo: https://github.com/psf/black-pre-commit-mirror
-    rev: '26.3.1'
+    rev: '26.5.1'
     hooks:
       - id: black
         exclude: ^pyabc2/sources/_lzstring.py
diff --git a/pyproject.toml b/pyproject.toml
index 3fc9cf3..76624c2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -69,6 +69,10 @@ exclude = ["^venv"]
 install_types = true
 ignore_missing_imports = true
 
+[[tool.mypy.overrides]]
+module = "pyabc2.sources._lzstring"
+ignore_errors = true
+
 [tool.pyright]
 ignore = ["pyabc2/sources/_lzstring.py"]