diff --git a/.golangci.yml b/.golangci.yml
index a6d09044..dc162832 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -15,21 +15,28 @@ linters:
    - dogsled
    - dupl
    - errcheck
-   - exportloopref
    - exhaustive
+   - exportloopref
+   - gci
    - goconst
    - gocyclo
+   - gocyclo
+   - godot
+   - godox
    - gofmt
-   - gci
+   - gofumpt
    - goimports
+   - gomnd
    - goprintffuncname
    - gosimple
    - govet
    - ineffassign
    - misspell
    - nakedret
+   - nestif
    - noctx
    - nolintlint
+   - revive
    - rowserrcheck
    - staticcheck
    - structcheck
@@ -39,5 +46,3 @@ linters:
    - unused
    - varcheck
    - whitespace
-   - godot
-   - godox
diff --git a/pkg/cmd/root.go b/pkg/cmd/root.go
index 090cb7da..e5e5b907 100644
--- a/pkg/cmd/root.go
+++ b/pkg/cmd/root.go
@@ -8,15 +8,13 @@ import (
 	"github.com/evilmartians/lefthook/pkg/lefthook"
 )
 
-var (
-	commands = [...]func(*lefthook.Options) *cobra.Command{
-		NewVersionCmd,
-		NewAddCmd,
-		NewInstallCmd,
-		NewUninstallCmd,
-		NewRunCmd,
-	}
-)
+var commands = [...]func(*lefthook.Options) *cobra.Command{
+	NewVersionCmd,
+	NewAddCmd,
+	NewInstallCmd,
+	NewUninstallCmd,
+	NewRunCmd,
+}
 
 func NewRootCmd() *cobra.Command {
 	options := lefthook.Options{
diff --git a/pkg/config/available_hooks.go b/pkg/config/available_hooks.go
index 8a64d196..7eb29f21 100644
--- a/pkg/config/available_hooks.go
+++ b/pkg/config/available_hooks.go
@@ -1,6 +1,6 @@
 package config
 
-// See: https://git-scm.com/docs/githooks
+// AvailableHooks - list of hooks taken from https://git-scm.com/docs/githooks.
 var AvailableHooks = [...]string{
 	"pre-applypatch",
 	"applypatch-msg",
diff --git a/pkg/config/load_test.go b/pkg/config/load_test.go
index cf6ac9b2..12c42f26 100644
--- a/pkg/config/load_test.go
+++ b/pkg/config/load_test.go
@@ -141,11 +141,11 @@ pre-push:
 	} {
 		fs := afero.Afero{Fs: afero.NewMemMapFs()}
 		t.Run(fmt.Sprintf("%d: %s", i, tt.name), func(t *testing.T) {
-			if err := fs.WriteFile("/lefthook.yml", tt.global, 0644); err != nil {
+			if err := fs.WriteFile("/lefthook.yml", tt.global, 0o644); err != nil {
 				t.Errorf("unexpected error: %s", err)
 			}
 
-			if err := fs.WriteFile("/lefthook-local.yml", tt.local, 0644); err != nil {
+			if err := fs.WriteFile("/lefthook-local.yml", tt.local, 0o644); err != nil {
 				t.Errorf("unexpected error: %s", err)
 			}
 
diff --git a/pkg/lefthook/add.go b/pkg/lefthook/add.go
index 6b8319c1..3e435c3c 100644
--- a/pkg/lefthook/add.go
+++ b/pkg/lefthook/add.go
@@ -7,6 +7,8 @@ import (
 	"github.com/evilmartians/lefthook/pkg/config"
 )
 
+const defaultDirMode = 0o755
+
 type AddArgs struct {
 	Hook string
 
@@ -44,10 +46,10 @@ func (l *Lefthook) Add(args *AddArgs) error {
 		sourceDir := filepath.Join(l.repo.RootPath, global, args.Hook)
 		sourceDirLocal := filepath.Join(l.repo.RootPath, local, args.Hook)
 		println("HI", sourceDir, sourceDirLocal)
-		if err = l.Fs.MkdirAll(sourceDir, 0755); err != nil {
+		if err = l.Fs.MkdirAll(sourceDir, defaultDirMode); err != nil {
 			return err
 		}
-		if err = l.Fs.MkdirAll(sourceDirLocal, 0755); err != nil {
+		if err = l.Fs.MkdirAll(sourceDirLocal, defaultDirMode); err != nil {
 			return err
 		}
 	}
diff --git a/pkg/lefthook/add_test.go b/pkg/lefthook/add_test.go
index 6bf35f02..a03add2c 100644
--- a/pkg/lefthook/add_test.go
+++ b/pkg/lefthook/add_test.go
@@ -124,10 +124,10 @@ source_dir_local: .source_dir_local
 			lefthook := &Lefthook{Options: &Options{Fs: fs}, repo: repo}
 
 			for file, content := range tt.existingFiles {
-				if err := fs.MkdirAll(filepath.Base(file), 0755); err != nil {
+				if err := fs.MkdirAll(filepath.Base(file), 0o755); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
-				if err := afero.WriteFile(fs, file, []byte(content), 0644); err != nil {
+				if err := afero.WriteFile(fs, file, []byte(content), 0o644); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
 			}
diff --git a/pkg/lefthook/install.go b/pkg/lefthook/install.go
index 4902a14f..df426a9f 100644
--- a/pkg/lefthook/install.go
+++ b/pkg/lefthook/install.go
@@ -18,6 +18,7 @@ import (
 
 const (
 	checksumHookFilename = "prepare-commit-msg"
+	configFileMode       = 0o666
 	configDefaultName    = "lefthook.yml"
 	configGlob           = "lefthook.y*ml"
 )
@@ -80,7 +81,7 @@ func (l *Lefthook) configExists(path string) bool {
 func (l *Lefthook) createConfig(path string) error {
 	file := filepath.Join(path, configDefaultName)
 
-	err := afero.WriteFile(l.Fs, file, templates.Config(), 0666)
+	err := afero.WriteFile(l.Fs, file, templates.Config(), configFileMode)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/lefthook/install_test.go b/pkg/lefthook/install_test.go
index d2e5c752..beb3377e 100644
--- a/pkg/lefthook/install_test.go
+++ b/pkg/lefthook/install_test.go
@@ -209,17 +209,17 @@ post-commit:
 		t.Run(fmt.Sprintf("%d: %s", n, tt.name), func(t *testing.T) {
 			// Create configuration file
 			if len(tt.config) > 0 {
-				if err := afero.WriteFile(fs, "/src/lefthook.yml", []byte(tt.config), 0644); err != nil {
+				if err := afero.WriteFile(fs, "/src/lefthook.yml", []byte(tt.config), 0o644); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
 			}
 
 			// Create files that should exist
 			for file, content := range tt.existingFiles {
-				if err := fs.MkdirAll(filepath.Base(file), 0755); err != nil {
+				if err := fs.MkdirAll(filepath.Base(file), 0o755); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
-				if err := afero.WriteFile(fs, file, []byte(content), 0755); err != nil {
+				if err := afero.WriteFile(fs, file, []byte(content), 0o755); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
 			}
diff --git a/pkg/lefthook/lefthook.go b/pkg/lefthook/lefthook.go
index 269de136..9246e6a8 100644
--- a/pkg/lefthook/lefthook.go
+++ b/pkg/lefthook/lefthook.go
@@ -13,6 +13,8 @@ import (
 	"github.com/evilmartians/lefthook/pkg/templates"
 )
 
+const hookFileMode = 0o755
+
 var lefthookContentRegexp = regexp.MustCompile("LEFTHOOK")
 
 type Options struct {
@@ -96,7 +98,8 @@ func (l *Lefthook) cleanHook(hook string, force bool) error {
 		if force {
 			log.Infof("File %s.old already exists, overwriting\n", hook)
 		} else {
-			return fmt.Errorf("Can't rename %s to %s.old - file already exists\n", hook, hook)
+			log.Errorf("Can't rename %s to %s.old - file already exists\n", hook, hook)
+			return fmt.Errorf("file %s.old already exists", hook)
 		}
 	}
 
@@ -112,7 +115,7 @@ func (l *Lefthook) cleanHook(hook string, force bool) error {
 func (l *Lefthook) addHook(hook, configChecksum string) error {
 	hookPath := filepath.Join(l.repo.HooksPath, hook)
 	err := afero.WriteFile(
-		l.Fs, hookPath, templates.Hook(hook, configChecksum), 0755,
+		l.Fs, hookPath, templates.Hook(hook, configChecksum), hookFileMode,
 	)
 	if err != nil {
 		return err
diff --git a/pkg/lefthook/uninstall_test.go b/pkg/lefthook/uninstall_test.go
index 29c2b79b..bd33740e 100644
--- a/pkg/lefthook/uninstall_test.go
+++ b/pkg/lefthook/uninstall_test.go
@@ -93,10 +93,10 @@ func TestLefthookUninstall(t *testing.T) {
 
 			// Prepare files that should exist
 			for file, content := range tt.existingFiles {
-				if err := fs.MkdirAll(filepath.Base(file), 0755); err != nil {
+				if err := fs.MkdirAll(filepath.Base(file), 0o755); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
-				if err := afero.WriteFile(fs, file, []byte(content), 0755); err != nil {
+				if err := afero.WriteFile(fs, file, []byte(content), 0o755); err != nil {
 					t.Errorf("unexpected error: %s", err)
 				}
 			}
diff --git a/pkg/log/log.go b/pkg/log/log.go
index c96866db..89002285 100644
--- a/pkg/log/log.go
+++ b/pkg/log/log.go
@@ -10,9 +10,7 @@ import (
 	"github.com/logrusorgru/aurora"
 )
 
-var (
-	std = New()
-)
+var std = New()
 
 type Level uint32