diff --git a/pyproject.toml b/pyproject.toml
index b531488..2e0a644 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,6 +55,7 @@ ci = "https://github.com/machow/quartodoc/actions"
 
 [project.optional-dependencies]
 dev = [
+    "griffe-pydantic",
     "pytest<8.0.0",
     "pytest-cov",
     "jupyterlab",