diff --git a/.github/workflows/changelog.yml b/.github/workflows/changelog.yml
index 1a3499ee6..04737aa8d 100644
--- a/.github/workflows/changelog.yml
+++ b/.github/workflows/changelog.yml
@@ -5,7 +5,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     steps:
     - uses: actions/checkout@v1
       with:
diff --git a/.github/workflows/esprc.yml b/.github/workflows/esprc.yml
index 83a2ac377..0d18749ed 100644
--- a/.github/workflows/esprc.yml
+++ b/.github/workflows/esprc.yml
@@ -8,7 +8,7 @@ on:
 
 jobs:
   parse:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     strategy:
       matrix:
         ap:
@@ -18,7 +18,7 @@ jobs:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         default: true
         override: true
@@ -28,7 +28,7 @@ jobs:
         args: --release --bin esprc -- ./schemas/APs/10303-${{ matrix.ap }}-aim-long.exp --check
 
   generate:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     strategy:
       matrix:
         ap:
@@ -38,7 +38,7 @@ jobs:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         components: rustfmt
         default: true
diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index f8f39d6a0..afce96945 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -7,12 +7,12 @@ on:
 
 jobs:
   pages:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         default: true
         override: true
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index f3376817e..6962fe995 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -8,12 +8,12 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     strategy:
       matrix:
         rust:
           - stable
-          - "1.56.0"  # MSRV (for edition 2021)
+          - ${{ vars.MSRV }}
     steps:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
@@ -30,12 +30,12 @@ jobs:
         args: --all-features
 
   check-format:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     steps:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         components: rustfmt
         default: true
@@ -46,12 +46,12 @@ jobs:
         args: -- --check
 
   doc:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     steps:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         default: true
         override: true
@@ -61,12 +61,12 @@ jobs:
         args: --no-deps
 
   clippy:
-    runs-on: ubuntu-20.04
+    runs-on: ${{ vars.UBUNTU_VERSION }}
     steps:
     - uses: actions/checkout@v1
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: "1.56.0"
+        toolchain: ${{ vars.MSRV }}
         profile: minimal
         components: clippy
         default: true
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8658e1571..4d02016e3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,7 @@ In addition to original Keep-a-Changelog, we use following rules:
 
 ### Internal
 - `cargo upgrade --workspace` https://github.com/ricosjp/ruststep/pull/240
+- Upgrading MSRV, updating dependent packages, and supporting the new clippy https://github.com/ricosjp/ruststep/pull/246
 
 ## 0.3.0 - 2022-06-14
 
diff --git a/Cargo.toml b/Cargo.toml
index 7ae596511..983f083a5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,4 +1,5 @@
 [workspace]
+resolver = "2"
 members = [
   "espr",
   "espr-derive",
diff --git a/espr-derive/Cargo.toml b/espr-derive/Cargo.toml
index 19142a02e..c1979a027 100644
--- a/espr-derive/Cargo.toml
+++ b/espr-derive/Cargo.toml
@@ -16,9 +16,9 @@ categories    = ["science", "development-tools"]
 proc-macro = true
 
 [dependencies]
-quote = "1.0.26"
-proc-macro2 = "1.0.53"
-syn = { version = "2.0.9", features = ["full", "extra-traits"] }
+quote = "1.0.37"
+proc-macro2 = "1.0.86"
+syn = { version = "2.0.77", features = ["full", "extra-traits"] }
 
 [dependencies.espr]
 version = "0.3.0"
@@ -27,5 +27,5 @@ path = "../espr"
 [dev-dependencies]
 ruststep = { version = "0.3.0", path = "../ruststep" }
 ruststep-derive = { version = "0.3.0", path = "../ruststep-derive" }
-serde = "1.0.158"
+serde = "1.0.210"
 derive-new = "0.5.9"
diff --git a/espr/Cargo.toml b/espr/Cargo.toml
index 719362145..bccd03215 100644
--- a/espr/Cargo.toml
+++ b/espr/Cargo.toml
@@ -18,20 +18,20 @@ categories    = ["science", "development-tools"]
 nom = "7.1.3"
 
 # For Rust code generation
-syn = "2.0.9"
-quote = "1.0.26"
-proc-macro2 = "1.0.53"
+syn = "2.0.56"
+quote = "1.0.37"
+proc-macro2 = "1.0.86"
 
 # Utilities
 Inflector = "0.11.4"
-derive_more = "0.99.17"
+derive_more = "0.99.18"
 itertools = "0.10.5"
 maplit = "1.0.2"
-thiserror = "1.0.40"
+thiserror = "1.0.63"
 structopt = "0.3.26"
 check_keyword = "0.2.0"
 katexit = "0.1.4"
 
 [dev-dependencies]
-insta = "1.29.0"
+insta = "1.39.0"
 maplit = "1.0.2"
diff --git a/espr/src/ast/mod.rs b/espr/src/ast/mod.rs
index 3330e3a13..5d6524980 100644
--- a/espr/src/ast/mod.rs
+++ b/espr/src/ast/mod.rs
@@ -25,18 +25,18 @@ pub trait Component: Sized {
     }
 }
 
-#[macro_export(local_inner_macro)]
+#[macro_export(local_inner_macros)]
 macro_rules! derive_ast_component {
     ($component:ty, $parser:path) => {
-        impl crate::ast::Component for $component {
+        impl $crate::ast::Component for $component {
             fn parse(
                 input: &str,
-            ) -> Result<(Self, Vec<crate::ast::Remark>), crate::ast::TokenizeFailed> {
+            ) -> Result<(Self, Vec<$crate::ast::Remark>), $crate::ast::TokenizeFailed> {
                 use nom::Finish;
                 let input = input.trim();
                 let (_input, parsed) = $parser(input)
                     .finish()
-                    .map_err(|err| crate::ast::TokenizeFailed::new(input, err))?;
+                    .map_err(|err| $crate::ast::TokenizeFailed::new(input, err))?;
                 Ok(parsed)
             }
         }
diff --git a/espr/src/codegen/rust/mod.rs b/espr/src/codegen/rust/mod.rs
index 60fc3e7b0..f747893db 100644
--- a/espr/src/codegen/rust/mod.rs
+++ b/espr/src/codegen/rust/mod.rs
@@ -7,6 +7,5 @@ mod simple_type;
 mod type_decl;
 mod type_ref;
 
-pub use entity::*;
 pub use format::rustfmt;
 pub use schema::*;
diff --git a/espr/src/codegen/rust/schema.rs b/espr/src/codegen/rust/schema.rs
index 33bd6e846..3744e3e35 100644
--- a/espr/src/codegen/rust/schema.rs
+++ b/espr/src/codegen/rust/schema.rs
@@ -36,10 +36,10 @@ impl Schema {
         let name = format_ident!("{}", self.name);
         let types = &self.types;
         let entities = &self.entities;
-        let type_decls = self.types.iter().filter(|e| match e {
-            TypeDecl::Enumeration(_) => false,
-            _ => true,
-        });
+        let type_decls = self
+            .types
+            .iter()
+            .filter(|e| !matches!(e, TypeDecl::Enumeration(_)));
         let entity_types: Vec<_> = entities
             .iter()
             .map(|e| format_ident!("{}", e.name.to_pascal_case()))
diff --git a/espr/src/ir/complex_entity.rs b/espr/src/ir/complex_entity.rs
index fedf14b82..ec2e4922d 100644
--- a/espr/src/ir/complex_entity.rs
+++ b/espr/src/ir/complex_entity.rs
@@ -49,17 +49,16 @@ pub struct PartialComplexEntity {
 
 impl PartialOrd for PartialComplexEntity {
     fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
-        match PartialOrd::partial_cmp(&self.indices.len(), &rhs.indices.len()) {
-            Some(Ordering::Equal) => PartialOrd::partial_cmp(&self.indices, &rhs.indices),
-            a @ Some(Ordering::Less) | a @ Some(Ordering::Greater) => a,
-            None => unreachable!(),
-        }
+        Some(self.cmp(rhs))
     }
 }
 
 impl Ord for PartialComplexEntity {
     fn cmp(&self, rhs: &Self) -> Ordering {
-        self.partial_cmp(rhs).unwrap()
+        match Ord::cmp(&self.indices.len(), &rhs.indices.len()) {
+            Ordering::Equal => Ord::cmp(&self.indices, &rhs.indices),
+            a @ Ordering::Less | a @ Ordering::Greater => a,
+        }
     }
 }
 
diff --git a/espr/src/ir/scope.rs b/espr/src/ir/scope.rs
index 5854a00d0..a65b55f8c 100644
--- a/espr/src/ir/scope.rs
+++ b/espr/src/ir/scope.rs
@@ -78,13 +78,7 @@ impl PartialOrd for Scope {
                 return None;
             }
         }
-        if self.0.len() == other.0.len() {
-            Some(cmp::Ordering::Equal)
-        } else if self.0.len() > other.0.len() {
-            Some(cmp::Ordering::Less)
-        } else {
-            Some(cmp::Ordering::Greater)
-        }
+        Some(other.0.len().cmp(&self.0.len()))
     }
 }
 
diff --git a/espr/src/parser/basis.rs b/espr/src/parser/basis.rs
index 268b77e4c..873471a2c 100644
--- a/espr/src/parser/basis.rs
+++ b/espr/src/parser/basis.rs
@@ -1,3 +1,5 @@
+#![allow(clippy::manual_is_ascii_check)]
+
 use super::{combinator::RawParseResult, reserved::is_reserved};
 use nom::{branch::*, character::complete::*, multi::*, sequence::*, Parser};
 
diff --git a/espr/src/parser/entity/mod.rs b/espr/src/parser/entity/mod.rs
index 131a9243f..6c5c58bdb 100644
--- a/espr/src/parser/entity/mod.rs
+++ b/espr/src/parser/entity/mod.rs
@@ -1,6 +1,7 @@
 mod attribute;
 mod derive;
 mod domain;
+#[allow(clippy::module_inception)]
 mod entity;
 mod inverse;
 mod unique;
diff --git a/espr/src/parser/schema.rs b/espr/src/parser/schema.rs
index ed7850805..e159c8b31 100644
--- a/espr/src/parser/schema.rs
+++ b/espr/src/parser/schema.rs
@@ -103,7 +103,7 @@ pub fn procedure_decl(input: &str) -> ParseResult<Procedure> {
 ///                    `)` \] `;` .
 pub fn procedure_head(input: &str) -> ParseResult<(String, Vec<FormalParameter>)> {
     let param = tuple((opt(tag("VAR")), formal_parameter)).map(|(var, mut params)| {
-        for mut param in &mut params {
+        for param in &mut params {
             param.is_variable = var.is_some();
         }
         params
diff --git a/ruststep-derive/Cargo.toml b/ruststep-derive/Cargo.toml
index 0a94ce980..e9b21d45c 100644
--- a/ruststep-derive/Cargo.toml
+++ b/ruststep-derive/Cargo.toml
@@ -17,17 +17,17 @@ categories    = ["science", "development-tools"]
 proc-macro = true
 
 [dependencies]
-quote = "1.0.26"
-proc-macro2 = "1.0.53"
-syn = { version = "2.0.9", features = ["full", "extra-traits"] }
-proc-macro-crate = "1.2.1"
+quote = "1.0.37"
+proc-macro2 = "1.0.86"
+syn = { version = "2.0.56", features = ["full", "extra-traits"] }
+proc-macro-crate = "1.3.0"
 Inflector = "0.11.4"
 proc-macro-error = "1.0.4"
 
 [dev-dependencies]
-serde = "1.0.158"
-trybuild = "1.0.80"
-insta = "1.29.0"
+serde = "1.0.210"
+trybuild = "1.0.90"
+insta = "1.39.0"
 
 [dev-dependencies.ruststep]
 path = "../ruststep"
diff --git a/ruststep-derive/src/common.rs b/ruststep-derive/src/common.rs
index 3125091ae..ae0762ab6 100644
--- a/ruststep-derive/src/common.rs
+++ b/ruststep-derive/src/common.rs
@@ -19,7 +19,7 @@ pub fn as_holder_path(input: &syn::Type) -> syn::Type {
         .clone()
         .try_into()
         .expect_or_abort("as_holder! only accepts espr-generated type");
-    ft.as_holder().into()
+    ft.into_holder().into()
 }
 
 pub fn as_visitor_ident(input: &syn::Ident) -> syn::Ident {
diff --git a/ruststep-derive/src/entity.rs b/ruststep-derive/src/entity.rs
index 98a65f7ab..7975063fb 100644
--- a/ruststep-derive/src/entity.rs
+++ b/ruststep-derive/src/entity.rs
@@ -85,7 +85,7 @@ impl FieldEntries {
                     }),
                     FieldType::Boxed(_) => abort_call_site!("Unexpected Box<T>"),
                 }
-                holder_types.push(ft.as_holder().as_place_holder().into());
+                holder_types.push(ft.into_holder().into_place_holder().into());
             } else {
                 into_owned.push(quote! { #ident });
                 holder_types.push(ft.into());
diff --git a/ruststep-derive/src/field_type.rs b/ruststep-derive/src/field_type.rs
index 54800a300..fd4233eb8 100644
--- a/ruststep-derive/src/field_type.rs
+++ b/ruststep-derive/src/field_type.rs
@@ -17,14 +17,14 @@ pub enum FieldType {
 }
 
 impl FieldType {
-    pub fn as_holder(self) -> Self {
+    pub fn into_holder(self) -> Self {
         match self {
             FieldType::Path(path) => {
                 let syn::Path {
                     leading_colon,
                     mut segments,
                 } = path;
-                let mut last_seg = segments.last_mut().unwrap();
+                let last_seg = segments.last_mut().unwrap();
                 match &mut last_seg.arguments {
                     syn::PathArguments::None => {
                         last_seg.ident = as_holder_ident(&last_seg.ident);
@@ -37,21 +37,21 @@ impl FieldType {
                 })
             }
             FieldType::Optional(ty) => {
-                let holder = ty.as_holder();
+                let holder = ty.into_holder();
                 FieldType::Optional(Box::new(holder))
             }
             FieldType::List(ty) => {
-                let holder = ty.as_holder();
+                let holder = ty.into_holder();
                 FieldType::List(Box::new(holder))
             }
             FieldType::Boxed(ty) => {
-                let holder = ty.as_holder();
+                let holder = ty.into_holder();
                 FieldType::Boxed(Box::new(holder))
             }
         }
     }
 
-    pub fn as_place_holder(self) -> Self {
+    pub fn into_place_holder(self) -> Self {
         let ruststep = ruststep_crate();
         match self {
             FieldType::Path(path) => {
@@ -59,15 +59,15 @@ impl FieldType {
                 FieldType::Path(path)
             }
             FieldType::Optional(ty) => {
-                let place_holder = ty.as_place_holder();
+                let place_holder = ty.into_place_holder();
                 FieldType::Optional(Box::new(place_holder))
             }
             FieldType::List(ty) => {
-                let place_holder = ty.as_place_holder();
+                let place_holder = ty.into_place_holder();
                 FieldType::List(Box::new(place_holder))
             }
             FieldType::Boxed(ty) => {
-                let place_holder = ty.as_place_holder();
+                let place_holder = ty.into_place_holder();
                 FieldType::Boxed(Box::new(place_holder))
             }
         }
@@ -77,18 +77,18 @@ impl FieldType {
 #[derive(Debug, Clone)]
 pub struct UnsupportedTypeError {}
 
-impl Into<Diagnostic> for UnsupportedTypeError {
-    fn into(self) -> Diagnostic {
-        Diagnostic::new(
+impl From<UnsupportedTypeError> for Diagnostic {
+    fn from(_: UnsupportedTypeError) -> Self {
+        Self::new(
             Level::Error,
             "Unsupported Type for ruststep and espr".to_string(),
         )
     }
 }
 
-impl Into<syn::Type> for FieldType {
-    fn into(self) -> syn::Type {
-        let path = match self {
+impl From<FieldType> for syn::Type {
+    fn from(field_type: FieldType) -> Self {
+        let path = match field_type {
             FieldType::Path(path) => path,
             FieldType::Optional(ty) => {
                 let ty: syn::Type = (*ty).into();
@@ -181,25 +181,25 @@ mod tests {
     fn as_holder() {
         let ty: syn::Type = syn::parse_str("T").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let holder = f.as_holder();
+        let holder = f.into_holder();
         let ans: syn::Type = syn::parse_str("THolder").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(holder), ans);
 
         let ty: syn::Type = syn::parse_str("Option<T>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let holder = f.as_holder();
+        let holder = f.into_holder();
         let ans: syn::Type = syn::parse_str("Option<THolder>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(holder), ans);
 
         let ty: syn::Type = syn::parse_str("Vec<T>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let holder = f.as_holder();
+        let holder = f.into_holder();
         let ans: syn::Type = syn::parse_str("Vec<THolder>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(holder), ans);
 
         let ty: syn::Type = syn::parse_str("Option<Vec<T>>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let holder = f.as_holder();
+        let holder = f.into_holder();
         let ans: syn::Type = syn::parse_str("Option<Vec<THolder>>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(holder), ans);
     }
@@ -208,27 +208,27 @@ mod tests {
     fn as_place_holder() {
         let ty: syn::Type = syn::parse_str("T").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let place_holder = f.as_holder().as_place_holder();
+        let place_holder = f.into_holder().into_place_holder();
         let ans: syn::Type = syn::parse_str("::ruststep::tables::PlaceHolder<THolder>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(place_holder), ans);
 
         let ty: syn::Type = syn::parse_str("Option<T>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let place_holder = f.as_holder().as_place_holder();
+        let place_holder = f.into_holder().into_place_holder();
         let ans: syn::Type =
             syn::parse_str("Option<::ruststep::tables::PlaceHolder<THolder>>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(place_holder), ans);
 
         let ty: syn::Type = syn::parse_str("Vec<T>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let place_holder = f.as_holder().as_place_holder();
+        let place_holder = f.into_holder().into_place_holder();
         let ans: syn::Type =
             syn::parse_str("Vec<::ruststep::tables::PlaceHolder<THolder>>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(place_holder), ans);
 
         let ty: syn::Type = syn::parse_str("Option<Vec<T>>").unwrap();
         let f: FieldType = ty.try_into().unwrap();
-        let place_holder = f.as_holder().as_place_holder();
+        let place_holder = f.into_holder().into_place_holder();
         let ans: syn::Type =
             syn::parse_str("Option<Vec<::ruststep::tables::PlaceHolder<THolder>>>").unwrap();
         assert_eq!(<FieldType as Into<syn::Type>>::into(place_holder), ans);
diff --git a/ruststep-derive/src/type_decl.rs b/ruststep-derive/src/type_decl.rs
index fc2a5f014..db1631e8c 100644
--- a/ruststep-derive/src/type_decl.rs
+++ b/ruststep-derive/src/type_decl.rs
@@ -217,7 +217,7 @@ impl FieldEntries {
                     }),
                     FieldType::Boxed(_) => abort_call_site!("Unexpected Box<T>"),
                 }
-                holder_types.push(ft.as_holder().as_place_holder().into());
+                holder_types.push(ft.into_holder().into_place_holder().into());
             } else {
                 into_owned.push(quote! { self.#index });
                 holder_types.push(ft.into());
diff --git a/ruststep/Cargo.toml b/ruststep/Cargo.toml
index fed5e0e6f..a2f042dcf 100644
--- a/ruststep/Cargo.toml
+++ b/ruststep/Cargo.toml
@@ -19,11 +19,11 @@ ap201 = []
 ap203 = []
 
 [dependencies]
-derive_more = "0.99.17"
+derive_more = "0.99.18"
 derive-new = "0.5.9"
 nom = "7.1.3"
-serde = { version = "1.0.158", features = ["derive"] }
-thiserror = "1.0.40"
+serde = { version = "1.0.210", features = ["derive"] }
+thiserror = "1.0.63"
 Inflector = "0.11.4"
 itertools = "0.10.5"
 
@@ -32,7 +32,7 @@ path = "../ruststep-derive"
 version = "0.3.0"
 
 [dev-dependencies]
-anyhow = "1.0.70"
+anyhow = "1.0.89"
 maplit = "1.0.2"
 
 [dev-dependencies.espr-derive]
diff --git a/ruststep/src/ast/de/record.rs b/ruststep/src/ast/de/record.rs
index f269c8e26..416e12133 100644
--- a/ruststep/src/ast/de/record.rs
+++ b/ruststep/src/ast/de/record.rs
@@ -25,7 +25,7 @@ impl<'de, 'record> de::Deserializer<'de> for &'record Record {
     {
         if name == self.name {
             if let Parameter::List(ref parameters) = self.parameter {
-                return visitor.visit_map(RecordStructDeserializer::new(fields, &parameters));
+                return visitor.visit_map(RecordStructDeserializer::new(fields, parameters));
             }
         }
         Self::deserialize_any(self, visitor)
diff --git a/ruststep/src/ast/de/subsuper.rs b/ruststep/src/ast/de/subsuper.rs
index 7be54b742..dbecaeb3b 100644
--- a/ruststep/src/ast/de/subsuper.rs
+++ b/ruststep/src/ast/de/subsuper.rs
@@ -49,7 +49,7 @@ impl<'de, 'record> de::MapAccess<'de> for SubSuperRecordDeserializer<'record> {
             let key: K::Value = seed.deserialize(key)?;
             Ok(Some(key))
         } else {
-            return Ok(None);
+            Ok(None)
         }
     }
 
diff --git a/ruststep/src/parser/basic.rs b/ruststep/src/parser/basic.rs
index aa0e202a2..c7a4c1eb8 100644
--- a/ruststep/src/parser/basic.rs
+++ b/ruststep/src/parser/basic.rs
@@ -1,5 +1,7 @@
 //! Parser for basic alphabets defined in the table 1 of ISO-10303-21
 
+#![allow(clippy::manual_is_ascii_check)]
+
 use super::combinator::*;
 use nom::{
     branch::alt,
diff --git a/ruststep/src/tables.rs b/ruststep/src/tables.rs
index 6467dab1e..d4c3bdb63 100644
--- a/ruststep/src/tables.rs
+++ b/ruststep/src/tables.rs
@@ -194,7 +194,10 @@ pub fn insert_record<'de, T: de::Deserialize<'de>>(
     id: u64,
     record: &Record,
 ) -> crate::error::Result<()> {
-    if let Some(_) = table.insert(id, de::Deserialize::deserialize(record)?) {
+    if table
+        .insert(id, de::Deserialize::deserialize(record)?)
+        .is_some()
+    {
         Err(Error::DuplicatedEntity(id))
     } else {
         Ok(())