diff --git a/pyproject.toml b/pyproject.toml
index 62055140..80c5eaff 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Mathematics",
 ]
 urls = {repository = "https://github.com/patrick-kidger/diffrax" }
-dependencies = ["jax>=0.4.38", "jaxtyping>=0.2.24", "typing_extensions>=4.5.0", "typeguard==2.13.3", "equinox>=0.11.10", "lineax>=0.0.5", "optimistix>=0.0.7"]
+dependencies = ["jax>=0.4.38", "jaxtyping>=0.2.24", "typing_extensions>=4.5.0", "typeguard==2.13.3", "equinox>=0.11.10", "lineax>=0.0.5", "optimistix>=0.0.9"]
 
 [build-system]
 requires = ["hatchling"]