diff --git a/src/jaxsim/physics/model/physics_model.py b/src/jaxsim/physics/model/physics_model.py
index 85832c0f7..86ce19018 100644
--- a/src/jaxsim/physics/model/physics_model.py
+++ b/src/jaxsim/physics/model/physics_model.py
@@ -100,8 +100,8 @@ def __post_init__(self):
                 [self._link_inertias_dict[l.index] for l in ordered_links]
             )
 
-            s_min = jnp.hstack([j.position_limit[0] for j in ordered_joints])
-            s_max = jnp.hstack([j.position_limit[1] for j in ordered_joints])
+            s_min = jnp.array([j.position_limit[0] for j in ordered_joints])
+            s_max = jnp.array([j.position_limit[1] for j in ordered_joints])
             self._joint_position_limits_min = jnp.vstack([s_min, s_max]).min(axis=0)
             self._joint_position_limits_max = jnp.vstack([s_min, s_max]).max(axis=0)