diff --git a/wrappers/rust/icicle-curves/icicle-bls12-377/src/tree/mod.rs b/wrappers/rust/icicle-curves/icicle-bls12-377/src/tree/mod.rs
index 14af731e2..b575bff7c 100644
--- a/wrappers/rust/icicle-curves/icicle-bls12-377/src/tree/mod.rs
+++ b/wrappers/rust/icicle-curves/icicle-bls12-377/src/tree/mod.rs
@@ -24,6 +24,6 @@ pub(crate) mod tests {
         let ctx = device_context::DeviceContext::default();
         let sponge = Poseidon::load(2, &ctx).unwrap();
 
-        check_build_field_merkle_tree::<_, _, Bls12_377TreeBuilder>(25, 2, &sponge, &sponge, ScalarField::zero());
+        check_build_field_merkle_tree::<_, _, Bls12_377TreeBuilder>(18, 2, &sponge, &sponge, ScalarField::zero());
     }
 }
diff --git a/wrappers/rust/icicle-curves/icicle-bls12-381/src/tree/mod.rs b/wrappers/rust/icicle-curves/icicle-bls12-381/src/tree/mod.rs
index 1860c9fb6..8690198d1 100644
--- a/wrappers/rust/icicle-curves/icicle-bls12-381/src/tree/mod.rs
+++ b/wrappers/rust/icicle-curves/icicle-bls12-381/src/tree/mod.rs
@@ -24,6 +24,6 @@ pub(crate) mod tests {
         let ctx = device_context::DeviceContext::default();
         let sponge = Poseidon::load(2, &ctx).unwrap();
 
-        check_build_field_merkle_tree::<_, _, Bls12_381TreeBuilder>(25, 2, &sponge, &sponge, ScalarField::zero());
+        check_build_field_merkle_tree::<_, _, Bls12_381TreeBuilder>(18, 2, &sponge, &sponge, ScalarField::zero());
     }
 }