diff --git a/packages/python/pyproject.toml b/packages/python/pyproject.toml
index 9096f5c..292dbb0 100644
--- a/packages/python/pyproject.toml
+++ b/packages/python/pyproject.toml
@@ -28,7 +28,7 @@ classifiers = [
   "Programming Language :: Python :: Implementation :: CPython",
   "Programming Language :: Python :: Implementation :: PyPy",
 ]
-dependencies = ["attrs>=21.3.0", "cattrs"]
+dependencies = ["attrs>=21.3.0", "cattrs!=23.2.1"]
 
 [project.urls]
 Issues = "https://github.com/microsoft/lsprotocol/issues"
diff --git a/requirements.in b/requirements.in
index d115049..4824f09 100644
--- a/requirements.in
+++ b/requirements.in
@@ -4,7 +4,7 @@
 # 2) pip-compile --generate-hashes --upgrade ./requirements.in
 
 attrs
-cattrs
+cattrs!=23.2.1
 jsonschema
 importlib_resources
 pytest