diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index a9871e6..34b30ed 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -13,12 +13,13 @@ jobs:
       uses: actions/checkout@v3
     - name: build
       run: docker-compose run go-json
+
   test:
     name: Test
     strategy:
       matrix:
         os: [ "ubuntu-latest", "macos-latest", "windows-latest" ]
-        go-version: [ "1.18", "1.19", "1.20" ]
+        go-version: [ "1.19", "1.20", "1.21" ]
     runs-on: ${{ matrix.os }}
     steps:
     - name: setup Go ${{ matrix.go-version }}
@@ -35,6 +36,20 @@ jobs:
         GOGC: 1
     - name: test with race detector
       run: go test -v -race ./... -count=1
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+      - name: setup Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: '1.21'
+      - name: lint
+        run: |
+          make lint
   bench:
     name: Benchmark
     runs-on: ubuntu-latest
@@ -42,7 +57,7 @@ jobs:
       - name: setup Go
         uses: actions/setup-go@v3
         with:
-          go-version: '1.20'
+          go-version: '1.21'
       - name: checkout ( feature )
         uses: actions/checkout@v3
       - name: run benchmark ( feature )
@@ -57,16 +72,17 @@ jobs:
         run: cd benchmarks && go test -bench GoJson | tee $HOME/old.txt
       - name: compare benchmark results
         run: benchstat $HOME/old.txt $HOME/new.txt
+
   coverage:
     name: Coverage
     runs-on: ubuntu-latest
     steps:
+      - name: checkout
+        uses: actions/checkout@v3
       - name: setup Go
         uses: actions/setup-go@v3
         with:
-          go-version: '1.20'
-      - name: checkout
-        uses: actions/checkout@v3
+          go-version: '1.21'
       - name: measure coverage
         run: make cover
       - uses: codecov/codecov-action@v3
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
deleted file mode 100644
index aa73ee3..0000000
--- a/.github/workflows/lint.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-name: lint
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-jobs:
-  golangci:
-    name: lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: golangci/golangci-lint-action@v3
-        with:
-          version: v1.45.2
-          args: --timeout=5m
diff --git a/.golangci.yml b/.golangci.yml
index 57ae5a5..977acca 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -56,6 +56,9 @@ linters:
     - cyclop
     - containedctx
     - revive
+    - nosnakecase
+    - exhaustruct
+    - depguard
 
 issues:
   exclude-rules:
diff --git a/Makefile b/Makefile
index 5bbfc4c..c030577 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ golangci-lint: | $(BIN_DIR)
 		GOLANGCI_LINT_TMP_DIR=$$(mktemp -d); \
 		cd $$GOLANGCI_LINT_TMP_DIR; \
 		go mod init tmp; \
-		GOBIN=$(BIN_DIR) go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.48.0; \
+		GOBIN=$(BIN_DIR) go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.54.2; \
 		rm -rf $$GOLANGCI_LINT_TMP_DIR; \
 	}
 
diff --git a/encode.go b/encode.go
index 4bd899f..c517382 100644
--- a/encode.go
+++ b/encode.go
@@ -52,7 +52,7 @@ func (e *Encoder) EncodeContext(ctx context.Context, v interface{}, optFuncs ...
 	rctx.Option.Flag |= encoder.ContextOption
 	rctx.Option.Context = ctx
 
-	err := e.encodeWithOption(rctx, v, optFuncs...)
+	err := e.encodeWithOption(rctx, v, optFuncs...) //nolint: contextcheck
 
 	encoder.ReleaseRuntimeContext(rctx)
 	return err
@@ -120,7 +120,7 @@ func marshalContext(ctx context.Context, v interface{}, optFuncs ...EncodeOption
 		optFunc(rctx.Option)
 	}
 
-	buf, err := encode(rctx, v)
+	buf, err := encode(rctx, v) //nolint: contextcheck
 	if err != nil {
 		encoder.ReleaseRuntimeContext(rctx)
 		return nil, err
diff --git a/go.mod b/go.mod
index 58a1488..f5b57ff 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
 module github.com/goccy/go-json
 
-go 1.12
+go 1.19
diff --git a/internal/cmd/generator/main.go b/internal/cmd/generator/main.go
index 0712cd0..326f527 100644
--- a/internal/cmd/generator/main.go
+++ b/internal/cmd/generator/main.go
@@ -7,7 +7,7 @@ import (
 	"go/parser"
 	"go/printer"
 	"go/token"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -273,11 +273,11 @@ func (t OpType) FieldToOmitEmptyField() OpType {
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(path, buf, 0644)
+	return os.WriteFile(path, buf, 0644)
 }
 
 func generateVM() error {
-	file, err := ioutil.ReadFile("vm.go.tmpl")
+	file, err := os.ReadFile("vm.go.tmpl")
 	if err != nil {
 		return err
 	}
@@ -295,7 +295,7 @@ func generateVM() error {
 		if err != nil {
 			return err
 		}
-		if err := ioutil.WriteFile(path, source, 0644); err != nil {
+		if err := os.WriteFile(path, source, 0644); err != nil {
 			return err
 		}
 	}
diff --git a/internal/decoder/unmarshal_text.go b/internal/decoder/unmarshal_text.go
index 6d37993..d711d0f 100644
--- a/internal/decoder/unmarshal_text.go
+++ b/internal/decoder/unmarshal_text.go
@@ -147,7 +147,7 @@ func (d *unmarshalTextDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int
 	return nil, 0, fmt.Errorf("json: unmarshal text decoder does not support decode path")
 }
 
-func unquoteBytes(s []byte) (t []byte, ok bool) {
+func unquoteBytes(s []byte) (t []byte, ok bool) { //nolint: nonamedreturns
 	length := len(s)
 	if length < 2 || s[0] != '"' || s[length-1] != '"' {
 		return
diff --git a/internal/encoder/string.go b/internal/encoder/string.go
index e4152b2..4abb841 100644
--- a/internal/encoder/string.go
+++ b/internal/encoder/string.go
@@ -1,3 +1,27 @@
+// This files's string processing codes are inspired by https://github.com/segmentio/encoding.
+// The license notation is as follows.
+//
+// # MIT License
+//
+// Copyright (c) 2019 Segment.io, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
 package encoder
 
 import (
diff --git a/internal/runtime/rtype.go b/internal/runtime/rtype.go
index 4db10de..37cfe35 100644
--- a/internal/runtime/rtype.go
+++ b/internal/runtime/rtype.go
@@ -252,7 +252,6 @@ func IfaceIndir(*Type) bool
 //go:noescape
 func RType2Type(t *Type) reflect.Type
 
-//go:nolint structcheck
 type emptyInterface struct {
 	_   *Type
 	ptr unsafe.Pointer
diff --git a/json.go b/json.go
index 413cb20..fb18065 100644
--- a/json.go
+++ b/json.go
@@ -89,31 +89,31 @@ type UnmarshalerContext interface {
 //
 // Examples of struct field tags and their meanings:
 //
-//   // Field appears in JSON as key "myName".
-//   Field int `json:"myName"`
+//	// Field appears in JSON as key "myName".
+//	Field int `json:"myName"`
 //
-//   // Field appears in JSON as key "myName" and
-//   // the field is omitted from the object if its value is empty,
-//   // as defined above.
-//   Field int `json:"myName,omitempty"`
+//	// Field appears in JSON as key "myName" and
+//	// the field is omitted from the object if its value is empty,
+//	// as defined above.
+//	Field int `json:"myName,omitempty"`
 //
-//   // Field appears in JSON as key "Field" (the default), but
-//   // the field is skipped if empty.
-//   // Note the leading comma.
-//   Field int `json:",omitempty"`
+//	// Field appears in JSON as key "Field" (the default), but
+//	// the field is skipped if empty.
+//	// Note the leading comma.
+//	Field int `json:",omitempty"`
 //
-//   // Field is ignored by this package.
-//   Field int `json:"-"`
+//	// Field is ignored by this package.
+//	Field int `json:"-"`
 //
-//   // Field appears in JSON as key "-".
-//   Field int `json:"-,"`
+//	// Field appears in JSON as key "-".
+//	Field int `json:"-,"`
 //
 // The "string" option signals that a field is stored as JSON inside a
 // JSON-encoded string. It applies only to fields of string, floating point,
 // integer, or boolean types. This extra level of encoding is sometimes used
 // when communicating with JavaScript programs:
 //
-//    Int64String int64 `json:",string"`
+//	Int64String int64 `json:",string"`
 //
 // The key name will be used if it's a non-empty string consisting of
 // only Unicode letters, digits, and ASCII punctuation except quotation
@@ -166,7 +166,6 @@ type UnmarshalerContext interface {
 // JSON cannot represent cyclic data structures and Marshal does not
 // handle them. Passing cyclic structures to Marshal will result in
 // an infinite recursion.
-//
 func Marshal(v interface{}) ([]byte, error) {
 	return MarshalWithOption(v)
 }
@@ -264,14 +263,13 @@ func MarshalIndentWithOption(v interface{}, prefix, indent string, optFuncs ...E
 //
 // The JSON null value unmarshals into an interface, map, pointer, or slice
 // by setting that Go value to nil. Because null is often used in JSON to mean
-// ``not present,'' unmarshaling a JSON null into any other Go type has no effect
+// “not present,” unmarshaling a JSON null into any other Go type has no effect
 // on the value and produces no error.
 //
 // When unmarshaling quoted strings, invalid UTF-8 or
 // invalid UTF-16 surrogate pairs are not treated as an error.
 // Instead, they are replaced by the Unicode replacement
 // character U+FFFD.
-//
 func Unmarshal(data []byte, v interface{}) error {
 	return unmarshal(data, v)
 }
@@ -299,7 +297,6 @@ func UnmarshalNoEscape(data []byte, v interface{}, optFuncs ...DecodeOptionFunc)
 //	Number, for JSON numbers
 //	string, for JSON string literals
 //	nil, for JSON null
-//
 type Token = json.Token
 
 // A Number represents a JSON number literal.