diff --git a/src/jaxsim/api/data.py b/src/jaxsim/api/data.py
index 8a878d382..b1f2230de 100644
--- a/src/jaxsim/api/data.py
+++ b/src/jaxsim/api/data.py
@@ -172,7 +172,7 @@ def build(
             dtype=float,
         ).squeeze()
 
-        gravity = jnp.zeros(3, dtype=float).at[2].set(-standard_gravity)
+        gravity = jnp.zeros(3).at[2].set(-standard_gravity)
 
         joint_positions = jnp.atleast_1d(
             jnp.array(
diff --git a/src/jaxsim/rbda/contacts/rigid.py b/src/jaxsim/rbda/contacts/rigid.py
index 52dc0a5b3..7c6d1f6ac 100644
--- a/src/jaxsim/rbda/contacts/rigid.py
+++ b/src/jaxsim/rbda/contacts/rigid.py
@@ -88,7 +88,7 @@ class RigidContacts(ContactModel):
     )
 
     terrain: jax_dataclasses.Static[Terrain] = dataclasses.field(
-        default_factory=FlatTerrain
+        default_factory=FlatTerrain.build
     )
 
     @classmethod