diff --git a/mjx/mujoco/mjx/_src/types.py b/mjx/mujoco/mjx/_src/types.py
index 6bed72c2..69caeebc 100644
--- a/mjx/mujoco/mjx/_src/types.py
+++ b/mjx/mujoco/mjx/_src/types.py
@@ -575,6 +575,7 @@ class ModelC(PyTreeNode):
   flex_bvhnum: jax.Array
   actuator_plugin: jax.Array
   sensor_plugin: jax.Array
+  sensor_intprm: jax.Array
   plugin: jax.Array