diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6f4010..83d4c54 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.3.1] - 2022-06-08
+### Fixed
+- Missing commas between items is output JSON Objects.
+
+### Changed
+- Release profile for smaller binary size.
+- Updated deps to latest.
+- Linter suggested updates.
+
 ## [0.3.0] - 2022-04-06
 ### Changed
 - Lexer token return signature reducing its size from 12->8 bytes
@@ -39,8 +48,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Initial release.
 
-[Unreleased]: https://github.com/rust-playground/ksql/compare/v0.3.0...HEAD
-[0.2.0]: https://github.com/rust-playground/ksql/compare/v0.2.0...v0.3.0
+[Unreleased]: https://github.com/rust-playground/ksql/compare/v0.3.1...HEAD
+[0.3.1]: https://github.com/rust-playground/ksql/compare/v0.3.0...v0.3.1
+[0.3.0]: https://github.com/rust-playground/ksql/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/rust-playground/ksql/compare/v0.1.2...v0.2.0
 [0.1.2]: https://github.com/rust-playground/ksql/compare/v0.1.1...v0.1.2
 [0.1.1]: https://github.com/rust-playground/ksql/compare/v0.1.0...v0.1.1
diff --git a/Cargo.toml b/Cargo.toml
index af58d41..162507e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "ksql"
 description = "A JSON data expression lexer, parser, cli and library"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 readme = "README.md"
@@ -16,11 +16,11 @@ keywords = [
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-anyhow = "1.0.56"
+anyhow = "1.0.57"
 atty = "0.2.14"
-clap = { version = "3.1.8", features = ["derive"] }
+clap = { version = "3.1.18", features = ["derive"] }
 gjson = "0.8.1"
-thiserror = "1.0.30"
+thiserror = "1.0.31"
 
 [dev-dependencies]
 criterion = { version = "0.3.5", features = ["html_reports"] }
@@ -34,4 +34,6 @@ harness = false
 
 [profile.release]
 lto = true
+strip = true
+codegen-units = 1
 panic = 'abort'
diff --git a/src/lexer.rs b/src/lexer.rs
index ac0e0e0..8d02737 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -33,7 +33,7 @@
 use thiserror::Error;
 
 /// The lexed token.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Token {
     pub start: u32,
     pub len: u16,
@@ -41,7 +41,7 @@ pub struct Token {
 }
 
 /// The kind of `Token`.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum TokenKind {
     Identifier,
     QuotedString,
@@ -162,7 +162,7 @@ where
 pub type Result<T> = std::result::Result<T, Error>;
 
 /// Error type for the lexer.
-#[derive(Error, Debug, PartialEq)]
+#[derive(Error, Debug, PartialEq, Eq)]
 pub enum Error {
     #[error("invalid identifier: {0}")]
     InvalidIdentifier(String),
@@ -185,7 +185,7 @@ pub enum Error {
 
 /// Try to lex a single token from the input stream.
 fn tokenize_single_token(data: &[u8]) -> Result<(TokenKind, u16)> {
-    let b = match data.get(0) {
+    let b = match data.first() {
         Some(b) => b,
         None => panic!("invalid data passed"),
     };
diff --git a/src/parser.rs b/src/parser.rs
index 8905bf2..22edfa6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -18,7 +18,7 @@ use crate::lexer::{TokenKind, Tokenizer};
 use anyhow::anyhow;
 use gjson::Kind;
 use std::collections::BTreeMap;
-use std::fmt::{Debug, Display, Formatter};
+use std::fmt::{Debug, Display, Formatter, Write};
 use thiserror::Error;
 
 /// Represents the calculated Expression result.
@@ -43,8 +43,9 @@ impl Display for Value {
                 let mut s = String::new();
                 s.push('{');
                 for (k, v) in o.iter() {
-                    s.push_str(&format!(r#""{}":{}"#, k, v));
+                    let _ = write!(s, r#""{}":{},"#, k, v);
                 }
+                s = s.trim_end_matches(',').to_string();
                 s.push('}');
                 s
             }),
@@ -52,7 +53,7 @@ impl Display for Value {
                 let mut s = String::new();
                 s.push('[');
                 for v in a.iter() {
-                    s.push_str(&format!("{},", v));
+                    let _ = write!(s, "{},", v);
                 }
                 s = s.trim_end_matches(',').to_string();
                 s.push(']');
@@ -740,7 +741,7 @@ impl Expression for Arr {
 pub type Result<T> = std::result::Result<T, Error>;
 
 /// Error type for the expression parser.
-#[derive(Error, Debug, PartialEq)]
+#[derive(Error, Debug, PartialEq, Eq)]
 pub enum Error {
     #[error("unsupported type comparison: {0}")]
     UnsupportedTypeComparison(String),