diff --git a/python/requirements/ml/rllib-test-requirements.txt b/python/requirements/ml/rllib-test-requirements.txt
index bd025015d8d2..3f7230c6fa10 100644
--- a/python/requirements/ml/rllib-test-requirements.txt
+++ b/python/requirements/ml/rllib-test-requirements.txt
@@ -6,7 +6,7 @@ imageio==2.34.2
 opencv-python-headless==4.9.0.80
 
 # For testing MuJoCo envs with gymnasium.
-mujoco==3.2.4
+mujoco==3.4.0
 dm_control==1.0.12; python_version < "3.12"
 
 # For tests on PettingZoo's multi-agent envs.