diff --git a/pyproject.toml b/pyproject.toml
index b4b0b4f..127ed35 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -57,7 +57,7 @@ dev = [
     "mypy",
     "ruff==0.4.1",
     "pre-commit",
-    "jupyter-book",
+    "jupyter-book<2",
     "mlflow",
 ]