diff --git a/mjx/pyproject.toml b/mjx/pyproject.toml
index 387bb3bb..7b64c743 100644
--- a/mjx/pyproject.toml
+++ b/mjx/pyproject.toml
@@ -31,7 +31,7 @@ dependencies = [
     "etils[epath]",
     "jax",
     "jaxlib",
-    "mujoco",
+    "mujoco>=3.1.5.dev0",
     "scipy",
     "trimesh",
 ]
@@ -44,4 +44,4 @@ mjx-viewer = "mujoco.mjx.viewer:main"
 Homepage = "https://github.com/google-deepmind/mujoco/tree/main/mjx"
 Documentation = "https://mujoco.readthedocs.io/en/3.1.5"
 Repository = "https://github.com/google-deepmind/mujoco/tree/main/mjx"
-Changelog = "https://mujoco.readthedocs.io/en/3.1.5/changelog.html"
+Changelog = "https://mujoco.readthedocs.io/en/3.1.5/changelog.html"
\ No newline at end of file