diff --git a/CHANGELOG.md b/CHANGELOG.md
index e61d43ed..18724bd0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Update `criterion` dev-dependency to 0.5
+
 ## [0.16.0] - 2023-10-11
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index 8d6b144e..c00dd7f7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,7 +37,7 @@ backtrace = {version = "0.3", optional = true}
 dusk-cdf = {version = "0.5", optional = true}
 
 [dev-dependencies]
-criterion = "0.3"
+criterion = "0.5"
 tempdir = "0.3"
 rand = "0.8"
 rkyv = {version = "0.7", default-features = false, features = ["size_32"]}
diff --git a/refactor_circuit.md b/refactor_circuit.md
deleted file mode 100644
index e694bd7e..00000000
--- a/refactor_circuit.md
+++ /dev/null
@@ -1,51 +0,0 @@
-Matteo's suggestion of restructuring the `Circuit` trait.
-
-1. Without the need to retain the private or public input values:
-```rust
-fn op<F>(f: F, a: u32, b: u32) -> u32 where F: Fn(u32, u32) -> u32 {
-    f(a, b)
-}
-
-fn add(a: u32, b: u32) -> u32 {
-    a + b
-}
-
-fn mul(a: u32, b: u32) -> u32 {
-    a * b
-}
-```
-
-2. With the option of retaining the private and public input values:
-```rust
-struct Foo<F>  where F: Fn(u32, u32) -> u32 {
-    a: u32,
-    b: u32,
-    callback: F
-}
-
-impl<F> Foo<F> where F: Fn(u32, u32) -> u32 {
-    fn calc(&self) -> u32 {
-        (self.callback)(self.a, self.b)
-    }
-}
-
-fn main() {
-
-    let foo = Foo {
-        a: 10,
-        b: 20,
-        callback: add,
-    };
-
-    println!("add: {}", op(add, 10, 20));
-    println!("mul: {}", op(mul, 10, 20));
-
-    println!("foo add: {}", foo.calc());
-}
-```
-
-Notes:
-- The funcitons `add` and `mul` would be different circuit implementation, returning the size of the circuit.
-- I wouldn't know how to search for the circuit implementation in the AST though.
-
-3. Another approach is the restructuring of the `Circuit` trait as proposed by Ed
diff --git a/rust-toolchain b/rust-toolchain
index fdd6c827..4ab37737 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2022-09-14
+nightly-2023-05-24
diff --git a/src/debugger.rs b/src/debugger.rs
index 87514804..b4560825 100644
--- a/src/debugger.rs
+++ b/src/debugger.rs
@@ -10,7 +10,6 @@ use std::env;
 use std::path::PathBuf;
 
 use dusk_bls12_381::BlsScalar;
-use dusk_bytes::Serializable;
 use dusk_cdf::{
     BaseConfig, Config, EncodableConstraint, EncodableSource, EncodableWitness,
     Encoder, EncoderContextFileProvider, Polynomial, Selectors, WiredWitnesses,
diff --git a/src/permutation.rs b/src/permutation.rs
index a5717945..cf92fdd5 100644
--- a/src/permutation.rs
+++ b/src/permutation.rs
@@ -992,7 +992,7 @@ mod test {
         let gamma = BlsScalar::random(&mut OsRng);
         assert_ne!(gamma, beta);
 
-        //1. Compute the permutation polynomial using both methods
+        // 1. Compute the permutation polynomial using both methods
         let [s_sigma_1_poly, s_sigma_2_poly, s_sigma_3_poly, s_sigma_4_poly] =
             perm.compute_sigma_polynomials(n, domain);
         let (z_vec, numerator_components, denominator_components) =
@@ -1048,7 +1048,7 @@ mod test {
         }
         assert_eq!(a_0 * b_0.invert().unwrap(), BlsScalar::one());
 
-        //3. Now we perform the two checks that need to be done on the
+        // 3. Now we perform the two checks that need to be done on the
         // permutation polynomial (z)
         let z_poly = Polynomial::from_coefficients_vec(domain.ifft(&z_vec));
         //