diff --git a/noir_stdlib/src/ec/consts/te.nr b/noir_stdlib/src/ec/consts/te.nr
index b5847e77f34..1159ac558b0 100644
--- a/noir_stdlib/src/ec/consts/te.nr
+++ b/noir_stdlib/src/ec/consts/te.nr
@@ -8,9 +8,8 @@ struct BabyJubjub {
     suborder: Field,
 }
 
+#[field(bn254)]
 pub fn baby_jubjub() -> BabyJubjub {
-    assert(compat::is_bn254());
-
     BabyJubjub {
         // Baby Jubjub (ERC-2494) parameters in affine representation
         curve: TECurve::new(
diff --git a/noir_stdlib/src/hash.nr b/noir_stdlib/src/hash.nr
index fb79038a06c..67e01c36e1c 100644
--- a/noir_stdlib/src/hash.nr
+++ b/noir_stdlib/src/hash.nr
@@ -46,6 +46,7 @@ fn mimc<N>(x: Field, k: Field, constants: [Field; N], exp : Field) -> Field {
 global MIMC_BN254_ROUNDS = 91;
 
 //mimc implementation with hardcoded parameters for BN254 curve.
+#[field(bn254)]
 pub fn mimc_bn254<N>(array: [Field; N]) -> Field {
     //mimc parameters
     let exponent = 7;
diff --git a/noir_stdlib/src/hash/poseidon/bn254.nr b/noir_stdlib/src/hash/poseidon/bn254.nr
index fadf45138ab..f93ff577c97 100644
--- a/noir_stdlib/src/hash/poseidon/bn254.nr
+++ b/noir_stdlib/src/hash/poseidon/bn254.nr
@@ -7,6 +7,7 @@ use crate::hash::poseidon::apply_matrix;
 
 // Optimised permutation for this particular field; uses hardcoded rf and rp values,
 // which should agree with those in pos_conf.
+#[field(bn254)]
 pub fn permute<M,N,O>(
     pos_conf: PoseidonConfig<M, N>,
     mut state: [Field; O])
@@ -65,6 +66,7 @@ pub fn permute<M,N,O>(
 }
 
 // Corresponding absorption.
+#[field(bn254)]
 fn absorb<M,N,O,P>(
     pos_conf: PoseidonConfig<M, N>,
     mut state: [Field; O], // Initial state; usually [0; O]
@@ -98,6 +100,7 @@ fn absorb<M,N,O,P>(
 }
 
 // Variable-length Poseidon-128 sponge as suggested in second bullet point of §3 of https://eprint.iacr.org/2019/458.pdf
+#[field(bn254)]
 pub fn sponge<N>(msg: [Field; N]) -> Field {
     absorb(consts::x5_5_config(), [0;5], 4, 1, msg)[1]
 }
diff --git a/noir_stdlib/src/hash/poseidon/bn254/perm.nr b/noir_stdlib/src/hash/poseidon/bn254/perm.nr
index 8b2f93c2d92..890f54fdb3f 100644
--- a/noir_stdlib/src/hash/poseidon/bn254/perm.nr
+++ b/noir_stdlib/src/hash/poseidon/bn254/perm.nr
@@ -3,6 +3,7 @@ use crate::hash::poseidon::bn254::consts;
 use crate::hash::poseidon::bn254::permute;
 use crate::hash::poseidon::PoseidonConfig;
 
+#[field(bn254)]
 pub fn x5_2(mut state: [Field; 2]) -> [Field; 2] {
     state = permute(
         consts::x5_2_config(),
@@ -11,6 +12,7 @@ pub fn x5_2(mut state: [Field; 2]) -> [Field; 2] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_3(mut state: [Field; 3]) -> [Field; 3] {
     state = permute(
         consts::x5_3_config(),
@@ -19,6 +21,7 @@ pub fn x5_3(mut state: [Field; 3]) -> [Field; 3] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_4(mut state: [Field; 4]) -> [Field; 4] {
     state = permute(
         consts::x5_4_config(),
@@ -27,6 +30,7 @@ pub fn x5_4(mut state: [Field; 4]) -> [Field; 4] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_5(mut state: [Field; 5]) -> [Field; 5] {
     state = permute(
         consts::x5_5_config(),
@@ -35,6 +39,7 @@ pub fn x5_5(mut state: [Field; 5]) -> [Field; 5] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_6(mut state: [Field; 6]) -> [Field; 6] {
     state = permute(
         consts::x5_6_config(),
@@ -43,6 +48,7 @@ pub fn x5_6(mut state: [Field; 6]) -> [Field; 6] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_7(mut state: [Field; 7]) -> [Field; 7] {
     state = permute(
         consts::x5_7_config(),
@@ -51,6 +57,7 @@ pub fn x5_7(mut state: [Field; 7]) -> [Field; 7] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_8(mut state: [Field; 8]) -> [Field; 8] {
     state = permute(
         consts::x5_8_config(),
@@ -59,6 +66,7 @@ pub fn x5_8(mut state: [Field; 8]) -> [Field; 8] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_9(mut state: [Field; 9]) -> [Field; 9] {
     state = permute(
         consts::x5_9_config(),
@@ -67,6 +75,7 @@ pub fn x5_9(mut state: [Field; 9]) -> [Field; 9] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_10(mut state: [Field; 10]) -> [Field; 10] {
     state = permute(
         consts::x5_10_config(),
@@ -75,6 +84,7 @@ pub fn x5_10(mut state: [Field; 10]) -> [Field; 10] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_11(mut state: [Field; 11]) -> [Field; 11] {
     state = permute(
         consts::x5_11_config(),
@@ -83,6 +93,7 @@ pub fn x5_11(mut state: [Field; 11]) -> [Field; 11] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_12(mut state: [Field; 12]) -> [Field; 12] {
     state = permute(
         consts::x5_12_config(),
@@ -91,6 +102,7 @@ pub fn x5_12(mut state: [Field; 12]) -> [Field; 12] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_13(mut state: [Field; 13]) -> [Field; 13] {
     state = permute(
         consts::x5_13_config(),
@@ -99,6 +111,7 @@ pub fn x5_13(mut state: [Field; 13]) -> [Field; 13] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_14(mut state: [Field; 14]) -> [Field; 14] {
     state = permute(
         consts::x5_14_config(),
@@ -107,6 +120,7 @@ pub fn x5_14(mut state: [Field; 14]) -> [Field; 14] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_15(mut state: [Field; 15]) -> [Field; 15] {
     state = permute(
         consts::x5_15_config(),
@@ -115,6 +129,7 @@ pub fn x5_15(mut state: [Field; 15]) -> [Field; 15] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_16(mut state: [Field; 16]) -> [Field; 16] {
     state = permute(
         consts::x5_16_config(),
@@ -123,6 +138,7 @@ pub fn x5_16(mut state: [Field; 16]) -> [Field; 16] {
     state
 }
 
+#[field(bn254)]
 pub fn x5_17(mut state: [Field; 17]) -> [Field; 17] {
     state = permute(
         consts::x5_17_config(),