diff --git a/zkp/examples/round.rs b/zkp/examples/round.rs
index 0c69c873..4d9d0573 100644
--- a/zkp/examples/round.rs
+++ b/zkp/examples/round.rs
@@ -58,7 +58,7 @@ fn generate_instance(num_vars: usize) -> RoundInstance<FF> {
         num_vars,
         input.iter().map(|x| FF::new(decode(*x))).collect(),
     ));
-    let mut output_bits_info = BitDecompositionInstanceInfo {
+    let output_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: LOG_FT,
@@ -66,7 +66,7 @@ fn generate_instance(num_vars: usize) -> RoundInstance<FF> {
         num_instances: 2,
     };
 
-    let mut offset_bits_info = BitDecompositionInstanceInfo {
+    let offset_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: k_bits_len,
@@ -81,8 +81,8 @@ fn generate_instance(num_vars: usize) -> RoundInstance<FF> {
         delta,
         input,
         output,
-        &mut output_bits_info,
-        &mut offset_bits_info,
+        &output_bits_info,
+        &offset_bits_info,
     )
 }
 fn main() {
diff --git a/zkp/tests/test_lift.rs b/zkp/tests/test_lift.rs
index c5c6191b..e59ec429 100644
--- a/zkp/tests/test_lift.rs
+++ b/zkp/tests/test_lift.rs
@@ -170,7 +170,7 @@ fn test_trivial_zq_to_rq() {
     let evals_at_r = instance.evaluate(&kit.randomness);
     let evals_at_u = instance.evaluate(&kit.u);
 
-    let mut wrapper = kit.extract();
+    let wrapper = kit.extract();
 
     let mut lift_iop = LiftIOP::default();
     let mut verifier_trans = Transcript::<FF>::new();
@@ -180,7 +180,7 @@ fn test_trivial_zq_to_rq() {
 
     let (check, _) = lift_iop.verify(
         &mut verifier_trans,
-        &mut wrapper,
+        &wrapper,
         &evals_at_r,
         &evals_at_u,
         &info,
@@ -269,7 +269,7 @@ fn test_random_zq_to_rq() {
     let evals_at_r = instance.evaluate(&kit.randomness);
     let evals_at_u = instance.evaluate(&kit.u);
 
-    let mut wrapper = kit.extract();
+    let wrapper = kit.extract();
 
     let mut lift_iop = LiftIOP::default();
     let mut verifier_trans = Transcript::<FF>::new();
@@ -279,7 +279,7 @@ fn test_random_zq_to_rq() {
 
     let (check, _) = lift_iop.verify(
         &mut verifier_trans,
-        &mut wrapper,
+        &wrapper,
         &evals_at_r,
         &evals_at_u,
         &info,
@@ -352,10 +352,10 @@ fn test_random_zq_to_rq_extension_field() {
     lift_iop.generate_randomness(&mut verifier_trans, &info);
     lift_iop.generate_randomness_for_eq_function(&mut verifier_trans, &info);
 
-    let mut wrapper = kit.extract();
+    let wrapper = kit.extract();
     let (check, _) = lift_iop.verify(
         &mut verifier_trans,
-        &mut wrapper,
+        &wrapper,
         &evals_at_r,
         &evals_at_u,
         &info,
diff --git a/zkp/tests/test_lookup.rs b/zkp/tests/test_lookup.rs
index b4c11928..7aca983e 100644
--- a/zkp/tests/test_lookup.rs
+++ b/zkp/tests/test_lookup.rs
@@ -90,7 +90,7 @@ fn test_trivial_range_check() {
     lookup.prover_generate_first_randomness(&mut prover_trans, &mut instance);
     lookup.generate_second_randomness(&mut prover_trans, &info);
     lookup.generate_randomness_for_eq_function(&mut prover_trans, &info);
-    let kit = lookup.prove(&mut prover_trans, &mut instance);
+    let kit = lookup.prove(&mut prover_trans, &instance);
     let evals = instance.evaluate(&kit.randomness);
 
     let wrapper = kit.extract();
@@ -150,7 +150,7 @@ fn test_random_range_check() {
     lookup.prover_generate_first_randomness(&mut prover_trans, &mut instance);
     lookup.generate_second_randomness(&mut prover_trans, &info);
     lookup.generate_randomness_for_eq_function(&mut prover_trans, &info);
-    let kit = lookup.prove(&mut prover_trans, &mut instance);
+    let kit = lookup.prove(&mut prover_trans, &instance);
     let evals = instance.evaluate(&kit.randomness);
 
     let wrapper = kit.extract();
diff --git a/zkp/tests/test_round.rs b/zkp/tests/test_round.rs
index 426c04f6..49d8d99a 100644
--- a/zkp/tests/test_round.rs
+++ b/zkp/tests/test_round.rs
@@ -76,7 +76,7 @@ fn test_round_naive_iop() {
         num_vars,
         field_vec!(FF; 0, 1, 1, 2),
     ));
-    let mut output_bits_info = BitDecompositionInstanceInfo {
+    let output_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: LOG_FT,
@@ -84,7 +84,7 @@ fn test_round_naive_iop() {
         num_instances: 2,
     };
 
-    let mut offset_bits_info = BitDecompositionInstanceInfo {
+    let offset_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: k_bits_len,
@@ -99,8 +99,8 @@ fn test_round_naive_iop() {
         delta,
         input,
         output,
-        &mut output_bits_info,
-        &mut offset_bits_info,
+        &output_bits_info,
+        &offset_bits_info,
     );
 
     let info = instance.info();
@@ -149,7 +149,7 @@ fn test_round_random_iop() {
         num_vars,
         input.iter().map(|x| FF::new(decode(*x))).collect(),
     ));
-    let mut output_bits_info = BitDecompositionInstanceInfo {
+    let output_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: LOG_FT,
@@ -157,7 +157,7 @@ fn test_round_random_iop() {
         num_instances: 2,
     };
 
-    let mut offset_bits_info = BitDecompositionInstanceInfo {
+    let offset_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: k_bits_len,
@@ -172,8 +172,8 @@ fn test_round_random_iop() {
         delta,
         input,
         output,
-        &mut output_bits_info,
-        &mut offset_bits_info,
+        &output_bits_info,
+        &offset_bits_info,
     );
 
     let info = instance.info();
@@ -222,7 +222,7 @@ fn test_round_random_iop_extension_field() {
         num_vars,
         input.iter().map(|x| FF::new(decode(*x))).collect(),
     ));
-    let mut output_bits_info = BitDecompositionInstanceInfo {
+    let output_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: LOG_FT,
@@ -230,7 +230,7 @@ fn test_round_random_iop_extension_field() {
         num_instances: 2,
     };
 
-    let mut offset_bits_info = BitDecompositionInstanceInfo {
+    let offset_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: k_bits_len,
@@ -245,8 +245,8 @@ fn test_round_random_iop_extension_field() {
         delta,
         input,
         output,
-        &mut output_bits_info,
-        &mut offset_bits_info,
+        &output_bits_info,
+        &offset_bits_info,
     );
 
     let instance_ef = instance.to_ef::<EF>();
@@ -297,7 +297,7 @@ fn test_round_snark() {
         num_vars,
         input.iter().map(|x| FF::new(decode(*x))).collect(),
     ));
-    let mut output_bits_info = BitDecompositionInstanceInfo {
+    let output_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: LOG_FT,
@@ -305,7 +305,7 @@ fn test_round_snark() {
         num_instances: 2,
     };
 
-    let mut offset_bits_info = BitDecompositionInstanceInfo {
+    let offset_bits_info = BitDecompositionInstanceInfo {
         base,
         base_len,
         bits_len: k_bits_len,
@@ -320,8 +320,8 @@ fn test_round_snark() {
         delta,
         input,
         output,
-        &mut output_bits_info,
-        &mut offset_bits_info,
+        &output_bits_info,
+        &offset_bits_info,
     );
 
     let code_spec = ExpanderCodeSpec::new(0.1195, 0.0248, 1.9, BASE_FIELD_BITS, 10);