diff --git a/src/batch_hasher.rs b/src/batch_hasher.rs
index 6d2d81a1..2d568f80 100644
--- a/src/batch_hasher.rs
+++ b/src/batch_hasher.rs
@@ -83,7 +83,7 @@ where
 
 impl<F, A> Batcher<F, A>
 where
-    F: PrimeField,
+    F: PrimeField + ec_gpu::GpuName,
     A: Arity<F>,
 {
     pub fn strength(&self) -> Strength {
diff --git a/src/column_tree_builder.rs b/src/column_tree_builder.rs
index 024d87bf..26bf144b 100644
--- a/src/column_tree_builder.rs
+++ b/src/column_tree_builder.rs
@@ -2,7 +2,7 @@ use crate::batch_hasher::Batcher;
 use crate::error::Error;
 use crate::poseidon::{Poseidon, PoseidonConstants};
 use crate::tree_builder::{TreeBuilder, TreeBuilderTrait};
-use crate::{Arity, BatchHasher, Strength, NeptuneField};
+use crate::{Arity, BatchHasher, NeptuneField, Strength};
 
 use ff::{Field, PrimeField};
 use generic_array::{ArrayLength, GenericArray};
diff --git a/src/halo2_circuit.rs b/src/halo2_circuit.rs
index 1874e91f..27035570 100644
--- a/src/halo2_circuit.rs
+++ b/src/halo2_circuit.rs
@@ -361,6 +361,8 @@ where
         let width = A::to_usize() + 1;
         consts
             .round_constants
+            .as_ref()
+            .unwrap()
             .iter()
             .skip(round * width)
             .take(width)
@@ -415,6 +417,8 @@ where
 
         let round_consts = consts
             .round_constants
+            .as_ref()
+            .unwrap()
             .iter()
             .skip(round * width)
             .take(width);
@@ -459,6 +463,8 @@ where
 
         let round_consts = consts
             .round_constants
+            .as_ref()
+            .unwrap()
             .iter()
             .skip(round * width)
             .take(width);
@@ -528,12 +534,16 @@ where
 
         let round_consts_a = consts
             .round_constants
+            .as_ref()
+            .unwrap()
             .iter()
             .skip(round_a * width)
             .take(width);
 
         let round_consts_b = consts
             .round_constants
+            .as_ref()
+            .unwrap()
             .iter()
             .skip(round_b * width)
             .take(width);
diff --git a/src/proteus/gpu.rs b/src/proteus/gpu.rs
index 487ea394..4ee3afcd 100644
--- a/src/proteus/gpu.rs
+++ b/src/proteus/gpu.rs
@@ -161,7 +161,7 @@ where
 
 impl<F, A> ClBatchHasher<F, A>
 where
-    F: PrimeField,
+    F: PrimeField + ec_gpu::GpuName,
     A: Arity<F>,
 {
     pub(crate) fn strength(&self) -> Strength {
diff --git a/src/proteus/sources.rs b/src/proteus/sources.rs
index c0c4b713..e928328e 100644
--- a/src/proteus/sources.rs
+++ b/src/proteus/sources.rs
@@ -125,12 +125,11 @@ fn poseidon_source(field: &str, strength: &str, derived_constants: &DerivedConst
 /// The constants can be generated based on the the arity and the strength. The `derived_constants`
 /// parameter is a list of tuples, where the first element contains the standard strength
 /// parameters, the second element is the strengthed, and the third is the "even-partial" strength.
-/// parameters, the second element is the strengthed one.
 fn generate_program_from_constants<F>(
     derived_constants: &[(DerivedConstants, DerivedConstants, DerivedConstants)],
 ) -> String
-    where
-        F: GpuName + 'static,
+where
+    F: GpuName + 'static,
 {
     let mut source = vec![shared(&F::name())];
     for (standard, _strengthened, _even_partial) in derived_constants {
@@ -162,31 +161,31 @@ fn derive_constants(arity: usize) -> (DerivedConstants, DerivedConstants, Derive
 /// Kernels for certain arities are enabled by feature flags.
 pub fn generate_program() -> SourceBuilder {
     #[cfg(any(feature = "bls", feature = "pasta"))]
-        let derived_constants = vec![
+    let derived_constants = vec![
         #[cfg(feature = "arity2")]
-            derive_constants(2),
+        derive_constants(2),
         #[cfg(feature = "arity4")]
-            derive_constants(4),
+        derive_constants(4),
         #[cfg(feature = "arity8")]
-            derive_constants(8),
+        derive_constants(8),
         #[cfg(feature = "arity11")]
-            derive_constants(11),
+        derive_constants(11),
         #[cfg(feature = "arity16")]
-            derive_constants(16),
+        derive_constants(16),
         #[cfg(feature = "arity24")]
-            derive_constants(24),
+        derive_constants(24),
         #[cfg(feature = "arity36")]
-            derive_constants(36),
+        derive_constants(36),
     ];
 
     let source_builder = SourceBuilder::new();
 
     #[cfg(feature = "bls")]
-        let source_builder = source_builder
+    let source_builder = source_builder
         .add_field::<Fr>()
         .append_source(generate_program_from_constants::<Fr>(&derived_constants));
     #[cfg(feature = "pasta")]
-        let source_builder = source_builder
+    let source_builder = source_builder
         .add_field::<Fp>()
         .add_field::<Fv>()
         .append_source(generate_program_from_constants::<Fp>(&derived_constants))
diff --git a/src/tree_builder.rs b/src/tree_builder.rs
index 02fdd3ec..0b501b8d 100644
--- a/src/tree_builder.rs
+++ b/src/tree_builder.rs
@@ -1,7 +1,7 @@
 use crate::batch_hasher::Batcher;
 use crate::error::Error;
 use crate::poseidon::{Poseidon, PoseidonConstants};
-use crate::{Arity, BatchHasher, Strength, NeptuneField};
+use crate::{Arity, BatchHasher, NeptuneField, Strength};
 
 use ff::{Field, PrimeField};
 use generic_array::GenericArray;