diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 93167de..a8d5b63 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,13 +14,12 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v3
       - name: Setup Go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: 1.x
       - name: Lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.50.1
           args: --verbose
       - name: Test
         run: make test
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 1a29f6b..2d9aa3d 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -13,7 +13,7 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@master
     - name: Setup Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
         go-version: 1.x
     - name: Cross build
diff --git a/.golangci.yaml b/.golangci.yaml
index 28ffcb1..0c25b8a 100644
--- a/.golangci.yaml
+++ b/.golangci.yaml
@@ -25,7 +25,7 @@ linters-settings:
         arguments:
           - maxLitCount: "3"
             allowStrs: '""'
-            allowInts: "0,1,2,3,4,5,0700,0660"
+            allowInts: "0,1,2,3,4,5,0700,0660,0o700,0o660"
             allowFloats: "0.0,0.,1.0,1.,2.0,2."
       - name: blank-imports
       - name: context-as-argument
diff --git a/go.mod b/go.mod
index f388664..c2c9517 100644
--- a/go.mod
+++ b/go.mod
@@ -1,12 +1,15 @@
 module github.com/mattn/efm-langserver
 
-go 1.13
+go 1.20
 
 require (
-	github.com/kr/pretty v0.1.0 // indirect
 	github.com/mattn/go-unicodeclass v0.0.1
 	github.com/reviewdog/errorformat v0.0.0-20220309155058-b075c45b6d9a
 	github.com/sourcegraph/jsonrpc2 v0.1.0
-	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 )
+
+require (
+	github.com/kr/pretty v0.1.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
+)
diff --git a/langserver/duration.go b/langserver/duration.go
index b4e2901..c8c6d98 100644
--- a/langserver/duration.go
+++ b/langserver/duration.go
@@ -16,7 +16,7 @@ func (d Duration) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON method Unmash duration from string or decimal
 func (d *Duration) UnmarshalJSON(b []byte) error {
-	var v interface{}
+	var v any
 	if err := json.Unmarshal(b, &v); err != nil {
 		return err
 	}
@@ -37,7 +37,7 @@ func (d *Duration) UnmarshalJSON(b []byte) error {
 }
 
 // UnmarshalYAML method Unmash duration from string or decimal
-func (d *Duration) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (d *Duration) UnmarshalYAML(unmarshal func(any) error) error {
 	var s string
 	if err := unmarshal(&s); err != nil {
 		return err
diff --git a/langserver/handle_initialize.go b/langserver/handle_initialize.go
index 0b8a851..f464fad 100644
--- a/langserver/handle_initialize.go
+++ b/langserver/handle_initialize.go
@@ -9,7 +9,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleInitialize(_ context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleInitialize(_ context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_shutdown.go b/langserver/handle_shutdown.go
index 875fc44..345e782 100644
--- a/langserver/handle_shutdown.go
+++ b/langserver/handle_shutdown.go
@@ -6,7 +6,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleShutdown(_ context.Context, conn *jsonrpc2.Conn, _ *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleShutdown(_ context.Context, conn *jsonrpc2.Conn, _ *jsonrpc2.Request) (result any, err error) {
 	if h.lintTimer != nil {
 		h.lintTimer.Stop()
 	}
diff --git a/langserver/handle_text_document_code_action.go b/langserver/handle_text_document_code_action.go
index 2433902..153d53e 100644
--- a/langserver/handle_text_document_code_action.go
+++ b/langserver/handle_text_document_code_action.go
@@ -14,7 +14,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentCodeAction(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentCodeAction(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
@@ -27,7 +27,7 @@ func (h *langHandler) handleTextDocumentCodeAction(_ context.Context, _ *jsonrpc
 	return h.codeAction(params.TextDocument.URI, &params)
 }
 
-func (h *langHandler) executeCommand(params *ExecuteCommandParams) (interface{}, error) {
+func (h *langHandler) executeCommand(params *ExecuteCommandParams) (any, error) {
 	if len(params.Arguments) != 1 {
 		return nil, fmt.Errorf("invalid command")
 	}
@@ -170,7 +170,7 @@ func filterCommands(uri DocumentURI, commands []Command) []Command {
 		results = append(results, Command{
 			Title:     v.Title,
 			Command:   fmt.Sprintf("efm-langserver\t%s\t%s", v.Command, string(uri)),
-			Arguments: []interface{}{string(uri)},
+			Arguments: []any{string(uri)},
 		})
 	}
 	return results
diff --git a/langserver/handle_text_document_completion.go b/langserver/handle_text_document_completion.go
index 4d8ef90..15cd454 100644
--- a/langserver/handle_text_document_completion.go
+++ b/langserver/handle_text_document_completion.go
@@ -15,7 +15,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentCompletion(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentCompletion(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_definition.go b/langserver/handle_text_document_definition.go
index 2c14c85..07b4da7 100644
--- a/langserver/handle_text_document_definition.go
+++ b/langserver/handle_text_document_definition.go
@@ -5,7 +5,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -17,7 +16,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentDefinition(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentDefinition(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
@@ -51,7 +50,7 @@ func (h *langHandler) findTag(fname string, tag string) ([]Location, error) {
 		if token[0] == tag {
 			token[2] = strings.TrimRight(token[2], `;"`)
 			fullpath := filepath.Clean(filepath.Join(h.rootPath, token[1]))
-			b, err := ioutil.ReadFile(fullpath)
+			b, err := os.ReadFile(fullpath)
 			if err != nil {
 				continue
 			}
diff --git a/langserver/handle_text_document_did_change.go b/langserver/handle_text_document_did_change.go
index 22a0f02..188ab8c 100644
--- a/langserver/handle_text_document_did_change.go
+++ b/langserver/handle_text_document_did_change.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentDidChange(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentDidChange(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_did_close.go b/langserver/handle_text_document_did_close.go
index 4b54ef3..5f1d022 100644
--- a/langserver/handle_text_document_did_close.go
+++ b/langserver/handle_text_document_did_close.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentDidClose(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentDidClose(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_did_open.go b/langserver/handle_text_document_did_open.go
index 0842ea5..29384e8 100644
--- a/langserver/handle_text_document_did_open.go
+++ b/langserver/handle_text_document_did_open.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentDidOpen(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentDidOpen(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_did_save.go b/langserver/handle_text_document_did_save.go
index 67bbbef..5db0c1c 100644
--- a/langserver/handle_text_document_did_save.go
+++ b/langserver/handle_text_document_did_save.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentDidSave(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentDidSave(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_formatting.go b/langserver/handle_text_document_formatting.go
index fa40b56..32889bc 100644
--- a/langserver/handle_text_document_formatting.go
+++ b/langserver/handle_text_document_formatting.go
@@ -16,7 +16,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentFormatting(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentFormatting(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_hover.go b/langserver/handle_text_document_hover.go
index b9c6db4..bdae82e 100644
--- a/langserver/handle_text_document_hover.go
+++ b/langserver/handle_text_document_hover.go
@@ -15,7 +15,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentHover(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentHover(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_text_document_symbol.go b/langserver/handle_text_document_symbol.go
index 461e21f..52c234f 100644
--- a/langserver/handle_text_document_symbol.go
+++ b/langserver/handle_text_document_symbol.go
@@ -16,7 +16,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleTextDocumentSymbol(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleTextDocumentSymbol(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_workspace_did_change_configuration.go b/langserver/handle_workspace_did_change_configuration.go
index 01df7f9..163ad48 100644
--- a/langserver/handle_workspace_did_change_configuration.go
+++ b/langserver/handle_workspace_did_change_configuration.go
@@ -8,7 +8,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleWorkspaceDidChangeConfiguration(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleWorkspaceDidChangeConfiguration(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
@@ -21,7 +21,7 @@ func (h *langHandler) handleWorkspaceDidChangeConfiguration(_ context.Context, _
 	return h.didChangeConfiguration(&params.Settings)
 }
 
-func (h *langHandler) didChangeConfiguration(config *Config) (interface{}, error) {
+func (h *langHandler) didChangeConfiguration(config *Config) (any, error) {
 	if config.Languages != nil {
 		h.configs = *config.Languages
 	}
diff --git a/langserver/handle_workspace_did_change_workspace_folders.go b/langserver/handle_workspace_did_change_workspace_folders.go
index 35ff499..6f58091 100644
--- a/langserver/handle_workspace_did_change_workspace_folders.go
+++ b/langserver/handle_workspace_did_change_workspace_folders.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleDidChangeWorkspaceWorkspaceFolders(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleDidChangeWorkspaceWorkspaceFolders(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
@@ -20,7 +20,7 @@ func (h *langHandler) handleDidChangeWorkspaceWorkspaceFolders(_ context.Context
 	return h.didChangeWorkspaceFolders(&params)
 }
 
-func (h *langHandler) didChangeWorkspaceFolders(params *DidChangeWorkspaceFoldersParams) (result interface{}, err error) {
+func (h *langHandler) didChangeWorkspaceFolders(params *DidChangeWorkspaceFoldersParams) (result any, err error) {
 	var folders []string
 	for _, removed := range params.Event.Removed {
 		for _, folder := range h.folders {
diff --git a/langserver/handle_workspace_execute_command.go b/langserver/handle_workspace_execute_command.go
index a47db44..0cb0c89 100644
--- a/langserver/handle_workspace_execute_command.go
+++ b/langserver/handle_workspace_execute_command.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleWorkspaceExecuteCommand(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleWorkspaceExecuteCommand(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
diff --git a/langserver/handle_workspace_workspace_folders.go b/langserver/handle_workspace_workspace_folders.go
index c4fb1cc..85eab3a 100644
--- a/langserver/handle_workspace_workspace_folders.go
+++ b/langserver/handle_workspace_workspace_folders.go
@@ -7,7 +7,7 @@ import (
 	"github.com/sourcegraph/jsonrpc2"
 )
 
-func (h *langHandler) handleWorkspaceWorkspaceFolders(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handleWorkspaceWorkspaceFolders(_ context.Context, _ *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	if req.Params == nil {
 		return nil, &jsonrpc2.Error{Code: jsonrpc2.CodeInvalidParams}
 	}
@@ -15,7 +15,7 @@ func (h *langHandler) handleWorkspaceWorkspaceFolders(_ context.Context, _ *json
 	return h.workspaceFolders()
 }
 
-func (h *langHandler) workspaceFolders() (result interface{}, err error) {
+func (h *langHandler) workspaceFolders() (result any, err error) {
 	workspaces := []WorkspaceFolder{}
 	for _, workspace := range h.folders {
 		workspaces = append(workspaces, WorkspaceFolder{
diff --git a/langserver/handler.go b/langserver/handler.go
index 2106e3f..dbdfce0 100644
--- a/langserver/handler.go
+++ b/langserver/handler.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net/url"
 	"os"
@@ -300,7 +299,7 @@ func matchRootPath(fname string, markers []string) string {
 	dir := filepath.Dir(filepath.Clean(fname))
 	var prev string
 	for dir != prev {
-		files, _ := ioutil.ReadDir(dir)
+		files, _ := os.ReadDir(dir)
 		for _, file := range files {
 			name := file.Name()
 			isDir := file.IsDir()
@@ -646,7 +645,7 @@ func (h *langHandler) addFolder(folder string) {
 	}
 }
 
-func (h *langHandler) handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) (result interface{}, err error) {
+func (h *langHandler) handle(ctx context.Context, conn *jsonrpc2.Conn, req *jsonrpc2.Request) (result any, err error) {
 	switch req.Method {
 	case "initialize":
 		return h.handleInitialize(ctx, conn, req)
@@ -700,3 +699,10 @@ func replaceCommandInputFilename(command, fname, rootPath string) string {
 
 	return command
 }
+
+func succeeded(err error) bool {
+	exitErr, ok := err.(*exec.ExitError)
+	// When the context is canceled, the process is killed,
+	// and the exit code is -1
+	return ok && exitErr.ExitCode() < 0
+}
diff --git a/langserver/handler_go112.go b/langserver/handler_go112.go
deleted file mode 100644
index 639fb86..0000000
--- a/langserver/handler_go112.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build !go1.13
-
-package langserver
-
-func succeeded(err error) bool {
-	return err == nil
-}
diff --git a/langserver/handler_go113.go b/langserver/handler_go113.go
deleted file mode 100644
index 249b682..0000000
--- a/langserver/handler_go113.go
+++ /dev/null
@@ -1,14 +0,0 @@
-// +build go1.13
-
-package langserver
-
-import (
-	"os/exec"
-)
-
-func succeeded(err error) bool {
-	exitErr, ok := err.(*exec.ExitError)
-	// When the context is canceled, the process is killed,
-	// and the exit code is -1
-	return ok && exitErr.ExitCode() < 0
-}
diff --git a/langserver/lsp.go b/langserver/lsp.go
index 931079f..a1364ba 100644
--- a/langserver/lsp.go
+++ b/langserver/lsp.go
@@ -197,7 +197,7 @@ type PublishDiagnosticsParams struct {
 }
 
 // FormattingOptions is
-type FormattingOptions map[string]interface{}
+type FormattingOptions map[string]any
 
 // DocumentFormattingParams is
 type DocumentFormattingParams struct {
@@ -278,16 +278,16 @@ const (
 
 // Command is
 type Command struct {
-	Title     string        `json:"title" yaml:"title"`
-	Command   string        `json:"command" yaml:"command"`
-	Arguments []interface{} `json:"arguments,omitempty" yaml:"arguments,omitempty"`
-	OS        string        `json:"-" yaml:"os,omitempty"`
+	Title     string `json:"title" yaml:"title"`
+	Command   string `json:"command" yaml:"command"`
+	Arguments []any  `json:"arguments,omitempty" yaml:"arguments,omitempty"`
+	OS        string `json:"-" yaml:"os,omitempty"`
 }
 
 // WorkspaceEdit is
 type WorkspaceEdit struct {
-	Changes         interface{} `json:"changes"`         // { [uri: DocumentUri]: TextEdit[]; };
-	DocumentChanges interface{} `json:"documentChanges"` // (TextDocumentEdit[] | (TextDocumentEdit | CreateFile | RenameFile | DeleteFile)[]);
+	Changes         any `json:"changes"`         // { [uri: DocumentUri]: TextEdit[]; };
+	DocumentChanges any `json:"documentChanges"` // (TextDocumentEdit[] | (TextDocumentEdit | CreateFile | RenameFile | DeleteFile)[]);
 }
 
 // CodeAction is
@@ -316,13 +316,13 @@ type CompletionItem struct {
 	AdditionalTextEdits []TextEdit          `json:"additionalTextEdits,omitempty"`
 	CommitCharacters    []string            `json:"commitCharacters,omitempty"`
 	Command             *Command            `json:"command,omitempty"`
-	Data                interface{}         `json:"data,omitempty"`
+	Data                any                 `json:"data,omitempty"`
 }
 
 // Hover is
 type Hover struct {
-	Contents interface{} `json:"contents"`
-	Range    *Range      `json:"range"`
+	Contents any    `json:"contents"`
+	Range    *Range `json:"range"`
 }
 
 // MarkedString is
@@ -348,15 +348,15 @@ type MarkupContent struct {
 
 // WorkDoneProgressParams is
 type WorkDoneProgressParams struct {
-	WorkDoneToken interface{} `json:"workDoneToken"`
+	WorkDoneToken any `json:"workDoneToken"`
 }
 
 // ExecuteCommandParams is
 type ExecuteCommandParams struct {
 	WorkDoneProgressParams
 
-	Command   string        `json:"command"`
-	Arguments []interface{} `json:"arguments,omitempty"`
+	Command   string `json:"command"`
+	Arguments []any  `json:"arguments,omitempty"`
 }
 
 // CodeActionKind is
@@ -382,7 +382,7 @@ type CodeActionContext struct {
 
 // PartialResultParams is
 type PartialResultParams struct {
-	PartialResultToken interface{} `json:"partialResultToken"`
+	PartialResultToken any `json:"partialResultToken"`
 }
 
 // CodeActionParams is
@@ -402,8 +402,8 @@ type DidChangeConfigurationParams struct {
 
 // NotificationMessage is
 type NotificationMessage struct {
-	Method string      `json:"message"`
-	Params interface{} `json:"params"`
+	Method string `json:"message"`
+	Params any    `json:"params"`
 }
 
 // DocumentDefinitionParams is
diff --git a/main.go b/main.go
index 34c6565..272e66f 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -56,7 +56,7 @@ func main() {
 		}
 
 		dir := filepath.Join(configHome, "efm-langserver")
-		if err := os.MkdirAll(dir, 0700); err != nil {
+		if err := os.MkdirAll(dir, 0o700); err != nil {
 			log.Fatal(err)
 		}
 
@@ -87,7 +87,7 @@ func main() {
 	}
 
 	if quiet {
-		log.SetOutput(ioutil.Discard)
+		log.SetOutput(io.Discard)
 	}
 
 	log.Println("efm-langserver: reading on stdin, writing on stdout")
@@ -102,7 +102,7 @@ func main() {
 	var connOpt []jsonrpc2.ConnOpt
 
 	if logfile != "" {
-		f, err := os.OpenFile(logfile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0660)
+		f, err := os.OpenFile(logfile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0o660)
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -114,7 +114,7 @@ func main() {
 	}
 
 	if quiet && (logfile == "" || loglevel < 5) {
-		connOpt = append(connOpt, jsonrpc2.LogMessages(log.New(ioutil.Discard, "", 0)))
+		connOpt = append(connOpt, jsonrpc2.LogMessages(log.New(io.Discard, "", 0)))
 	}
 
 	handler := langserver.NewHandler(config)