diff --git a/Arkworks/Cargo.toml b/Arkworks/Cargo.toml
index 1dc90d4f2..65d8be2c1 100644
--- a/Arkworks/Cargo.toml
+++ b/Arkworks/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "arkworks"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 kzg = { path = "../kzg" }
diff --git a/Cargo.lock b/Cargo.lock
index 3d6490157..bc8133172 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -312,7 +312,6 @@ dependencies = [
  "libc",
  "once_cell",
  "rand",
- "rand_pcg",
  "rayon",
  "sha2 0.10.6",
 ]
@@ -1042,15 +1041,6 @@ dependencies = [
  "getrandom",
 ]
 
-[[package]]
-name = "rand_pcg"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59cad018caf63deb318e5a4586d99a24424a364f40f1e5778c29aca23f4fc73e"
-dependencies = [
- "rand_core",
-]
-
 [[package]]
 name = "rayon"
 version = "1.6.1"
diff --git a/blst-from-scratch/Cargo.toml b/blst-from-scratch/Cargo.toml
index f10c640bc..aa8e28d4f 100644
--- a/blst-from-scratch/Cargo.toml
+++ b/blst-from-scratch/Cargo.toml
@@ -1,12 +1,11 @@
 [package]
 name = "blst_from_scratch"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 blst = { 'git' = 'https://github.com/supranational/blst.git' }
 rand = "0.8.4"
-rand_pcg = "0.3.1"
 kzg = { path = "../kzg" }
 kzg-bench = { path = "../kzg-bench" }
 rayon = { version = "1.5.1", optional = true }
diff --git a/ckzg/Cargo.toml b/ckzg/Cargo.toml
index 8a9f7a863..f2262136d 100644
--- a/ckzg/Cargo.toml
+++ b/ckzg/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "ckzg"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 kzg = { path = "../kzg" }
diff --git a/kzg-bench/Cargo.toml b/kzg-bench/Cargo.toml
index 3a60d1f2c..ed79eacf6 100644
--- a/kzg-bench/Cargo.toml
+++ b/kzg-bench/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "kzg-bench"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 kzg = { path = '../kzg' }
diff --git a/kzg/Cargo.toml b/kzg/Cargo.toml
index 567a7c39f..6b43b4058 100644
--- a/kzg/Cargo.toml
+++ b/kzg/Cargo.toml
@@ -1,4 +1,4 @@
 [package]
 name = "kzg"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
diff --git a/mcl/kzg-bench/Cargo.toml b/mcl/kzg-bench/Cargo.toml
index 5ef36afad..47615b00f 100644
--- a/mcl/kzg-bench/Cargo.toml
+++ b/mcl/kzg-bench/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "mcl_kzg_bench"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 mcl_rust = { path = '../kzg' }
diff --git a/mcl/kzg/Cargo.toml b/mcl/kzg/Cargo.toml
index eeaedcd09..df587bb0b 100644
--- a/mcl/kzg/Cargo.toml
+++ b/mcl/kzg/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.1"
 authors = ["MITSUNARI Shigeo <herumi@nifty.com>"]
 description = "a wrapper class/function of a pairing library; https://github.com/herumi/mcl"
 license = "BSD-3-Clause OR MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 cc = "1.0"
diff --git a/mcl/kzg/src/data_types/fr.rs b/mcl/kzg/src/data_types/fr.rs
index dc6d38b05..59f2f6c4e 100644
--- a/mcl/kzg/src/data_types/fr.rs
+++ b/mcl/kzg/src/data_types/fr.rs
@@ -95,7 +95,6 @@ impl Fr {
     }
 
     pub fn to_u64_arr(&self) -> [u64; 4] {
-        use std::convert::TryInto;
         let v: Vec<u64> = Fr::to_scalar(self)
             .chunks(8)
             .map(|ch| u64::from_le_bytes(ch.try_into().unwrap()))
diff --git a/zkcrypto/Cargo.toml b/zkcrypto/Cargo.toml
index d68815bd8..c9e100223 100644
--- a/zkcrypto/Cargo.toml
+++ b/zkcrypto/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "zkcrypto"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 kzg = { path = "../kzg"}