diff --git a/pyproject.toml b/pyproject.toml
index 6877bbae..2a5aea19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ classifiers = [
     'Topic :: Scientific/Engineering :: Artificial Intelligence',
 ]
 dependencies = [
-    "mujoco>=2.3.3",
+    "mujoco>=2.3.3, <3.0",
     "numpy>=1.21.0",
     "gymnasium>=0.26",
     "PettingZoo>=1.23.0",