diff --git a/cmd/gluetun/main.go b/cmd/gluetun/main.go
index ce48feed..aee10233 100644
--- a/cmd/gluetun/main.go
+++ b/cmd/gluetun/main.go
@@ -316,7 +316,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 
 	if allSettings.OpenVPN.Provider.PortForwarding.Enabled {
 		logger.Info("Clearing forwarded port status file %s", allSettings.OpenVPN.Provider.PortForwarding.Filepath)
-		if err := os.Remove(string(allSettings.OpenVPN.Provider.PortForwarding.Filepath)); err != nil {
+		if err := os.Remove(allSettings.OpenVPN.Provider.PortForwarding.Filepath); err != nil {
 			logger.Error(err)
 		}
 	}
diff --git a/internal/cli/clientkey.go b/internal/cli/clientkey.go
index 9531312c..b6801bb1 100644
--- a/internal/cli/clientkey.go
+++ b/internal/cli/clientkey.go
@@ -12,7 +12,7 @@ import (
 
 func (c *cli) ClientKey(args []string, openFile os.OpenFileFunc) error {
 	flagSet := flag.NewFlagSet("clientkey", flag.ExitOnError)
-	filepath := flagSet.String("path", string(constants.ClientKey), "file path to the client.key file")
+	filepath := flagSet.String("path", constants.ClientKey, "file path to the client.key file")
 	if err := flagSet.Parse(args); err != nil {
 		return err
 	}
diff --git a/internal/configuration/cyberghost.go b/internal/configuration/cyberghost.go
index 74dfcda5..85576b97 100644
--- a/internal/configuration/cyberghost.go
+++ b/internal/configuration/cyberghost.go
@@ -65,7 +65,7 @@ func (settings *Provider) readCyberghost(r reader) (err error) {
 }
 
 func readCyberghostClientKey(r reader) (clientKey string, err error) {
-	b, err := r.getFromFileOrSecretFile("OPENVPN_CLIENTKEY", string(constants.ClientKey))
+	b, err := r.getFromFileOrSecretFile("OPENVPN_CLIENTKEY", constants.ClientKey)
 	if err != nil {
 		return "", err
 	}
@@ -86,7 +86,7 @@ func extractClientKey(b []byte) (key string, err error) {
 }
 
 func readCyberghostClientCertificate(r reader) (clientCertificate string, err error) {
-	b, err := r.getFromFileOrSecretFile("OPENVPN_CLIENTCRT", string(constants.ClientCertificate))
+	b, err := r.getFromFileOrSecretFile("OPENVPN_CLIENTCRT", constants.ClientCertificate)
 	if err != nil {
 		return "", err
 	}
diff --git a/internal/configuration/openvpn.go b/internal/configuration/openvpn.go
index 75e3eb9c..22cec806 100644
--- a/internal/configuration/openvpn.go
+++ b/internal/configuration/openvpn.go
@@ -7,7 +7,6 @@ import (
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/constants"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/golibs/params"
 )
 
@@ -67,7 +66,7 @@ func (settings *OpenVPN) read(r reader) (err error) {
 		vpnsp = "private internet access"
 	}
 
-	settings.Provider.Name = models.VPNProvider(vpnsp)
+	settings.Provider.Name = vpnsp
 
 	settings.User, err = r.getFromEnvOrSecretFile("OPENVPN_USER", true, []string{"USER"})
 	if err != nil {
diff --git a/internal/configuration/privateinternetaccess.go b/internal/configuration/privateinternetaccess.go
index ae969a4d..82e69d0c 100644
--- a/internal/configuration/privateinternetaccess.go
+++ b/internal/configuration/privateinternetaccess.go
@@ -4,7 +4,6 @@ import (
 	"strconv"
 
 	"github.com/qdm12/gluetun/internal/constants"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/golibs/params"
 )
 
@@ -67,12 +66,11 @@ func (settings *Provider) readPrivateInternetAccess(r reader) (err error) {
 	}
 
 	if settings.PortForwarding.Enabled {
-		filepathStr, err := r.env.Path("PORT_FORWARDING_STATUS_FILE",
+		settings.PortForwarding.Filepath, err = r.env.Path("PORT_FORWARDING_STATUS_FILE",
 			params.Default("/tmp/gluetun/forwarded_port"), params.CaseSensitiveValue())
 		if err != nil {
 			return err
 		}
-		settings.PortForwarding.Filepath = models.Filepath(filepathStr)
 	}
 
 	return nil
diff --git a/internal/configuration/provider.go b/internal/configuration/provider.go
index d96cefd7..a722859a 100644
--- a/internal/configuration/provider.go
+++ b/internal/configuration/provider.go
@@ -7,29 +7,28 @@ import (
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/constants"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/golibs/params"
 )
 
 // Provider contains settings specific to a VPN provider.
 type Provider struct {
-	Name               models.VPNProvider `json:"name"`
+	Name               string             `json:"name"`
 	ServerSelection    ServerSelection    `json:"server_selection"`
 	ExtraConfigOptions ExtraConfigOptions `json:"extra_config"`
 	PortForwarding     PortForwarding     `json:"port_forwarding"`
 }
 
 func (settings *Provider) lines() (lines []string) {
-	lines = append(lines, lastIndent+strings.Title(string(settings.Name))+" settings:")
+	lines = append(lines, lastIndent+strings.Title(settings.Name)+" settings:")
 
-	lines = append(lines, indent+lastIndent+"Network protocol: "+string(settings.ServerSelection.Protocol))
+	lines = append(lines, indent+lastIndent+"Network protocol: "+settings.ServerSelection.Protocol)
 
 	if settings.ServerSelection.TargetIP != nil {
 		lines = append(lines, indent+lastIndent+"Target IP address: "+settings.ServerSelection.TargetIP.String())
 	}
 
 	var providerLines []string
-	switch strings.ToLower(string(settings.Name)) {
+	switch strings.ToLower(settings.Name) {
 	case "cyberghost":
 		providerLines = settings.cyberghostLines()
 	case "mullvad":
@@ -64,14 +63,8 @@ func commaJoin(slice []string) string {
 	return strings.Join(slice, ", ")
 }
 
-func readProtocol(env params.Env) (protocol models.NetworkProtocol, err error) {
-	s, err := env.Inside("PROTOCOL",
-		[]string{string(constants.TCP), string(constants.UDP)},
-		params.Default(string(constants.UDP)))
-	if err != nil {
-		return "", err
-	}
-	return models.NetworkProtocol(s), nil
+func readProtocol(env params.Env) (protocol string, err error) {
+	return env.Inside("PROTOCOL", []string{constants.TCP, constants.UDP}, params.Default(constants.UDP))
 }
 
 func readTargetIP(env params.Env) (targetIP net.IP, err error) {
@@ -82,7 +75,7 @@ var (
 	ErrInvalidProtocol = errors.New("invalid network protocol")
 )
 
-func readCustomPort(env params.Env, protocol models.NetworkProtocol,
+func readCustomPort(env params.Env, protocol string,
 	allowedTCP, allowedUDP []uint16) (port uint16, err error) {
 	port, err = readPortOrZero(env, "PORT")
 	if err != nil {
diff --git a/internal/configuration/provider_test.go b/internal/configuration/provider_test.go
index 13973905..35e0928c 100644
--- a/internal/configuration/provider_test.go
+++ b/internal/configuration/provider_test.go
@@ -6,7 +6,6 @@ import (
 
 	"github.com/golang/mock/gomock"
 	"github.com/qdm12/gluetun/internal/constants"
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/golibs/params/mock_params"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -108,7 +107,7 @@ func Test_Provider_lines(t *testing.T) {
 				},
 				PortForwarding: PortForwarding{
 					Enabled:  true,
-					Filepath: models.Filepath("/here"),
+					Filepath: string("/here"),
 				},
 			},
 			lines: []string{
@@ -207,7 +206,7 @@ func Test_readProtocol(t *testing.T) {
 	testCases := map[string]struct {
 		mockStr  string
 		mockErr  error
-		protocol models.NetworkProtocol
+		protocol string
 		err      error
 	}{
 		"error": {
diff --git a/internal/configuration/publicip.go b/internal/configuration/publicip.go
index ecc3acc8..2c8f4a17 100644
--- a/internal/configuration/publicip.go
+++ b/internal/configuration/publicip.go
@@ -4,13 +4,12 @@ import (
 	"strings"
 	"time"
 
-	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/golibs/params"
 )
 
 type PublicIP struct {
-	Period     time.Duration   `json:"period"`
-	IPFilepath models.Filepath `json:"ip_filepath"`
+	Period     time.Duration `json:"period"`
+	IPFilepath string        `json:"ip_filepath"`
 }
 
 func (settings *PublicIP) String() string {
@@ -25,7 +24,7 @@ func (settings *PublicIP) lines() (lines []string) {
 
 	lines = append(lines, lastIndent+"Public IP getter:")
 	lines = append(lines, indent+lastIndent+"Fetch period: "+settings.Period.String())
-	lines = append(lines, indent+lastIndent+"IP file: "+string(settings.IPFilepath))
+	lines = append(lines, indent+lastIndent+"IP file: "+settings.IPFilepath)
 
 	return lines
 }
@@ -36,13 +35,12 @@ func (settings *PublicIP) read(r reader) (err error) {
 		return err
 	}
 
-	filepathStr, err := r.env.Path("PUBLICIP_FILE", params.CaseSensitiveValue(),
+	settings.IPFilepath, err = r.env.Path("PUBLICIP_FILE", params.CaseSensitiveValue(),
 		params.Default("/tmp/gluetun/ip"),
 		params.RetroKeys([]string{"IP_STATUS_FILE"}, r.onRetroActive))
 	if err != nil {
 		return err
 	}
-	settings.IPFilepath = models.Filepath(filepathStr)
 
 	return nil
 }
diff --git a/internal/configuration/selection.go b/internal/configuration/selection.go
index 1b951f47..83a87717 100644
--- a/internal/configuration/selection.go
+++ b/internal/configuration/selection.go
@@ -2,14 +2,12 @@ package configuration
 
 import (
 	"net"
-
-	"github.com/qdm12/gluetun/internal/models"
 )
 
 type ServerSelection struct {
 	// Common
-	Protocol models.NetworkProtocol `json:"network_protocol"`
-	TargetIP net.IP                 `json:"target_ip,omitempty"`
+	Protocol string `json:"network_protocol"`
+	TargetIP net.IP `json:"target_ip,omitempty"`
 
 	// Cyberghost, PIA, Surfshark, Windscribe, Vyprvpn, NordVPN
 	Regions []string `json:"regions"`
@@ -44,12 +42,12 @@ type ExtraConfigOptions struct {
 
 // PortForwarding contains settings for port forwarding.
 type PortForwarding struct {
-	Enabled  bool            `json:"enabled"`
-	Filepath models.Filepath `json:"filepath"`
+	Enabled  bool   `json:"enabled"`
+	Filepath string `json:"filepath"`
 }
 
 func (p *PortForwarding) lines() (lines []string) {
 	return []string{
-		lastIndent + "File path: " + string(p.Filepath),
+		lastIndent + "File path: " + p.Filepath,
 	}
 }
diff --git a/internal/constants/openvpn.go b/internal/constants/openvpn.go
index e90a910c..3853cfa4 100644
--- a/internal/constants/openvpn.go
+++ b/internal/constants/openvpn.go
@@ -1,10 +1,6 @@
 package constants
 
-import (
-	"github.com/qdm12/gluetun/internal/models"
-)
-
 const (
-	TUN models.VPNDevice = "tun0"
-	TAP models.VPNDevice = "tap0"
+	TUN = "tun0"
+	TAP = "tap0"
 )
diff --git a/internal/constants/paths.go b/internal/constants/paths.go
index 9f985906..9cf716b6 100644
--- a/internal/constants/paths.go
+++ b/internal/constants/paths.go
@@ -1,34 +1,30 @@
 package constants
 
-import (
-	"github.com/qdm12/gluetun/internal/models"
-)
-
 const (
 	// UnboundConf is the file path to the Unbound configuration file.
-	UnboundConf models.Filepath = "/etc/unbound/unbound.conf"
+	UnboundConf string = "/etc/unbound/unbound.conf"
 	// ResolvConf is the file path to the system resolv.conf file.
-	ResolvConf models.Filepath = "/etc/resolv.conf"
+	ResolvConf string = "/etc/resolv.conf"
 	// CACertificates is the file path to the CA certificates file.
-	CACertificates models.Filepath = "/etc/ssl/certs/ca-certificates.crt"
+	CACertificates string = "/etc/ssl/certs/ca-certificates.crt"
 	// OpenVPNAuthConf is the file path to the OpenVPN auth file.
-	OpenVPNAuthConf models.Filepath = "/etc/openvpn/auth.conf"
+	OpenVPNAuthConf string = "/etc/openvpn/auth.conf"
 	// OpenVPNConf is the file path to the OpenVPN client configuration file.
-	OpenVPNConf models.Filepath = "/etc/openvpn/target.ovpn"
+	OpenVPNConf string = "/etc/openvpn/target.ovpn"
 	// PIAPortForward is the file path to the port forwarding JSON information for PIA servers.
-	PIAPortForward models.Filepath = "/gluetun/piaportforward.json"
+	PIAPortForward string = "/gluetun/piaportforward.json"
 	// TunnelDevice is the file path to tun device.
-	TunnelDevice models.Filepath = "/dev/net/tun"
+	TunnelDevice string = "/dev/net/tun"
 	// NetRoute is the path to the file containing information on the network route.
-	NetRoute models.Filepath = "/proc/net/route"
+	NetRoute string = "/proc/net/route"
 	// RootHints is the filepath to the root.hints file used by Unbound.
-	RootHints models.Filepath = "/etc/unbound/root.hints"
+	RootHints string = "/etc/unbound/root.hints"
 	// RootKey is the filepath to the root.key file used by Unbound.
-	RootKey models.Filepath = "/etc/unbound/root.key"
+	RootKey string = "/etc/unbound/root.key"
 	// Client key filepath, used by Cyberghost.
-	ClientKey models.Filepath = "/gluetun/client.key"
+	ClientKey string = "/gluetun/client.key"
 	// Client certificate filepath, used by Cyberghost.
-	ClientCertificate models.Filepath = "/gluetun/client.crt"
+	ClientCertificate string = "/gluetun/client.crt"
 	// Servers information filepath.
 	ServersData = "/gluetun/servers.json"
 )
diff --git a/internal/constants/vpn.go b/internal/constants/vpn.go
index 70341d29..5bf937d2 100644
--- a/internal/constants/vpn.go
+++ b/internal/constants/vpn.go
@@ -1,33 +1,29 @@
 package constants
 
-import (
-	"github.com/qdm12/gluetun/internal/models"
-)
-
 const (
 	// PrivateInternetAccess is a VPN provider.
-	PrivateInternetAccess models.VPNProvider = "private internet access"
+	PrivateInternetAccess = "private internet access"
 	// Mullvad is a VPN provider.
-	Mullvad models.VPNProvider = "mullvad"
+	Mullvad = "mullvad"
 	// Windscribe is a VPN provider.
-	Windscribe models.VPNProvider = "windscribe"
+	Windscribe = "windscribe"
 	// Surfshark is a VPN provider.
-	Surfshark models.VPNProvider = "surfshark"
+	Surfshark = "surfshark"
 	// Cyberghost is a VPN provider.
-	Cyberghost models.VPNProvider = "cyberghost"
+	Cyberghost = "cyberghost"
 	// Vyprvpn is a VPN provider.
-	Vyprvpn models.VPNProvider = "vyprvpn"
+	Vyprvpn = "vyprvpn"
 	// NordVPN is a VPN provider.
-	Nordvpn models.VPNProvider = "nordvpn"
+	Nordvpn = "nordvpn"
 	// PureVPN is a VPN provider.
-	Purevpn models.VPNProvider = "purevpn"
+	Purevpn = "purevpn"
 	// Privado is a VPN provider.
-	Privado models.VPNProvider = "privado"
+	Privado = "privado"
 )
 
 const (
 	// TCP is a network protocol (reliable and slower than UDP).
-	TCP models.NetworkProtocol = "tcp"
+	TCP string = "tcp"
 	// UDP is a network protocol (unreliable and faster than TCP).
-	UDP models.NetworkProtocol = "udp"
+	UDP string = "udp"
 )
diff --git a/internal/models/alias.go b/internal/models/alias.go
index 08b2c173..cedfab96 100644
--- a/internal/models/alias.go
+++ b/internal/models/alias.go
@@ -1,23 +1,6 @@
 package models
 
-import (
-	"fmt"
-	"strings"
-)
-
 type (
-	// VPNDevice is the device name used to tunnel using Openvpn.
-	VPNDevice string
-	// DNSHost is the DNS host to use for TLS validation.
-	DNSHost string
-	// URL is an HTTP(s) URL address.
-	URL string
-	// Filepath is a local filesytem file path.
-	Filepath string
-	// VPNProvider is the name of the VPN provider to be used.
-	VPNProvider string
-	// NetworkProtocol contains the network protocol to be used to communicate with the VPN servers.
-	NetworkProtocol string
 	// LoopStatus status such as stopped or running.
 	LoopStatus string
 )
@@ -25,41 +8,3 @@ type (
 func (ls LoopStatus) String() string {
 	return string(ls)
 }
-
-func marshalJSONString(s string) (data []byte, err error) {
-	return []byte(fmt.Sprintf("%q", s)), nil
-}
-
-func unmarshalJSONString(data []byte) (s string) {
-	s = string(data)
-	s = strings.TrimPrefix(s, "\"")
-	s = strings.TrimSuffix(s, "\"")
-	return s
-}
-
-func (v *VPNProvider) MarshalJSON() ([]byte, error) {
-	return marshalJSONString(string(*v))
-}
-
-func (v *VPNProvider) UnmarshalJSON(data []byte) error {
-	*v = VPNProvider(unmarshalJSONString(data))
-	return nil
-}
-
-func (n *NetworkProtocol) MarshalJSON() ([]byte, error) {
-	return marshalJSONString(string(*n))
-}
-
-func (n *NetworkProtocol) UnmarshalJSON(data []byte) error {
-	*n = NetworkProtocol(unmarshalJSONString(data))
-	return nil
-}
-
-func (f *Filepath) MarshalJSON() ([]byte, error) {
-	return marshalJSONString(string(*f))
-}
-
-func (f *Filepath) UnmarshalJSON(data []byte) error {
-	*f = Filepath(unmarshalJSONString(data))
-	return nil
-}
diff --git a/internal/models/alias_test.go b/internal/models/alias_test.go
deleted file mode 100644
index b17ce091..00000000
--- a/internal/models/alias_test.go
+++ /dev/null
@@ -1,41 +0,0 @@
-package models
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-)
-
-func Test_VPNProvider_JSON(t *testing.T) {
-	t.Parallel()
-	v := VPNProvider("name")
-	data, err := v.MarshalJSON()
-	require.NoError(t, err)
-	assert.Equal(t, []byte{0x22, 0x6e, 0x61, 0x6d, 0x65, 0x22}, data)
-	err = v.UnmarshalJSON(data)
-	require.NoError(t, err)
-	assert.Equal(t, VPNProvider("name"), v)
-}
-
-func Test_NetworkProtocol_JSON(t *testing.T) {
-	t.Parallel()
-	v := NetworkProtocol("name")
-	data, err := v.MarshalJSON()
-	require.NoError(t, err)
-	assert.Equal(t, []byte{0x22, 0x6e, 0x61, 0x6d, 0x65, 0x22}, data)
-	err = v.UnmarshalJSON(data)
-	require.NoError(t, err)
-	assert.Equal(t, NetworkProtocol("name"), v)
-}
-
-func Test_Filepath_JSON(t *testing.T) {
-	t.Parallel()
-	v := Filepath("name")
-	data, err := v.MarshalJSON()
-	require.NoError(t, err)
-	assert.Equal(t, []byte{0x22, 0x6e, 0x61, 0x6d, 0x65, 0x22}, data)
-	err = v.UnmarshalJSON(data)
-	require.NoError(t, err)
-	assert.Equal(t, Filepath("name"), v)
-}
diff --git a/internal/models/dns.go b/internal/models/dns.go
deleted file mode 100644
index 7c828748..00000000
--- a/internal/models/dns.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package models
-
-import "net"
-
-// DNSProviderData contains information for a DNS provider.
-type DNSProviderData struct {
-	IPs            []net.IP
-	SupportsTLS    bool
-	SupportsIPv6   bool
-	SupportsDNSSec bool
-	Host           DNSHost
-}
diff --git a/internal/models/openvpn.go b/internal/models/openvpn.go
index e518c072..c776678a 100644
--- a/internal/models/openvpn.go
+++ b/internal/models/openvpn.go
@@ -5,10 +5,10 @@ import (
 )
 
 type OpenVPNConnection struct {
-	IP       net.IP          `json:"ip"`
-	Port     uint16          `json:"port"`
-	Protocol NetworkProtocol `json:"protocol"`
-	Hostname string          `json:"hostname"` // Privado for tls verification
+	IP       net.IP `json:"ip"`
+	Port     uint16 `json:"port"`
+	Protocol string `json:"protocol"`
+	Hostname string `json:"hostname"` // Privado for tls verification
 }
 
 func (o *OpenVPNConnection) Equal(other OpenVPNConnection) bool {
diff --git a/internal/models/server.go b/internal/models/server.go
index 1f0eeef6..21a501a7 100644
--- a/internal/models/server.go
+++ b/internal/models/server.go
@@ -8,11 +8,11 @@ import (
 )
 
 type PIAServer struct {
-	Region      string          `json:"region"`
-	ServerName  string          `json:"server_name"`
-	Protocol    NetworkProtocol `json:"protocol"`
-	PortForward bool            `json:"port_forward"`
-	IP          net.IP          `json:"ip"`
+	Region      string `json:"region"`
+	ServerName  string `json:"server_name"`
+	Protocol    string `json:"protocol"`
+	PortForward bool   `json:"port_forward"`
+	IP          net.IP `json:"ip"`
 }
 
 func (p *PIAServer) String() string {
diff --git a/internal/openvpn/auth.go b/internal/openvpn/auth.go
index 2ca267c9..06ba129c 100644
--- a/internal/openvpn/auth.go
+++ b/internal/openvpn/auth.go
@@ -10,15 +10,14 @@ import (
 
 // WriteAuthFile writes the OpenVPN auth file to disk with the right permissions.
 func (c *configurator) WriteAuthFile(user, password string, puid, pgid int) error {
-	const filepath = string(constants.OpenVPNAuthConf)
-	file, err := c.os.OpenFile(filepath, os.O_RDONLY, 0)
+	file, err := c.os.OpenFile(constants.OpenVPNAuthConf, os.O_RDONLY, 0)
 
 	if err != nil && !os.IsNotExist(err) {
 		return err
 	}
 
 	if os.IsNotExist(err) {
-		file, err = c.os.OpenFile(filepath, os.O_WRONLY|os.O_CREATE, 0400)
+		file, err = c.os.OpenFile(constants.OpenVPNAuthConf, os.O_WRONLY|os.O_CREATE, 0400)
 		if err != nil {
 			return err
 		}
@@ -50,7 +49,7 @@ func (c *configurator) WriteAuthFile(user, password string, puid, pgid int) erro
 	}
 
 	c.logger.Info("username and password changed in %s", constants.OpenVPNAuthConf)
-	file, err = c.os.OpenFile(filepath, os.O_TRUNC|os.O_WRONLY, 0400)
+	file, err = c.os.OpenFile(constants.OpenVPNAuthConf, os.O_TRUNC|os.O_WRONLY, 0400)
 	if err != nil {
 		return err
 	}
diff --git a/internal/openvpn/command.go b/internal/openvpn/command.go
index 29324d5b..bc639b63 100644
--- a/internal/openvpn/command.go
+++ b/internal/openvpn/command.go
@@ -11,7 +11,7 @@ import (
 func (c *configurator) Start(ctx context.Context) (
 	stdoutLines, stderrLines chan string, waitError chan error, err error) {
 	c.logger.Info("starting openvpn")
-	return c.commander.Start(ctx, "openvpn", "--config", string(constants.OpenVPNConf))
+	return c.commander.Start(ctx, "openvpn", "--config", constants.OpenVPNConf)
 }
 
 func (c *configurator) Version(ctx context.Context) (string, error) {
diff --git a/internal/openvpn/loop.go b/internal/openvpn/loop.go
index 5e1b43cb..c265a98b 100644
--- a/internal/openvpn/loop.go
+++ b/internal/openvpn/loop.go
@@ -237,7 +237,7 @@ func (l *looper) portForward(ctx context.Context, wg *sync.WaitGroup,
 	if !settings.Provider.PortForwarding.Enabled {
 		return
 	}
-	syncState := func(port uint16) (pfFilepath models.Filepath) {
+	syncState := func(port uint16) (pfFilepath string) {
 		l.state.portForwardedMu.Lock()
 		defer l.state.portForwardedMu.Unlock()
 		l.state.portForwarded = port
@@ -251,8 +251,7 @@ func (l *looper) portForward(ctx context.Context, wg *sync.WaitGroup,
 }
 
 func writeOpenvpnConf(lines []string, openFile os.OpenFileFunc) error {
-	const filepath = string(constants.OpenVPNConf)
-	file, err := openFile(filepath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
+	file, err := openFile(constants.OpenVPNConf, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
 	if err != nil {
 		return err
 	}
diff --git a/internal/openvpn/tun.go b/internal/openvpn/tun.go
index 0b5cddb1..91e61978 100644
--- a/internal/openvpn/tun.go
+++ b/internal/openvpn/tun.go
@@ -11,7 +11,7 @@ import (
 // CheckTUN checks the tunnel device is present and accessible.
 func (c *configurator) CheckTUN() error {
 	c.logger.Info("checking for device %s", constants.TunnelDevice)
-	f, err := c.os.OpenFile(string(constants.TunnelDevice), os.O_RDWR, 0)
+	f, err := c.os.OpenFile(constants.TunnelDevice, os.O_RDWR, 0)
 	if err != nil {
 		return fmt.Errorf("TUN device is not available: %w", err)
 	}
@@ -32,12 +32,11 @@ func (c *configurator) CreateTUN() error {
 		minor = 200
 	)
 	dev := c.unix.Mkdev(major, minor)
-	if err := c.unix.Mknod(string(constants.TunnelDevice), unix.S_IFCHR, int(dev)); err != nil {
+	if err := c.unix.Mknod(constants.TunnelDevice, unix.S_IFCHR, int(dev)); err != nil {
 		return err
 	}
 
-	const filepath = string(constants.TunnelDevice)
-	file, err := c.os.OpenFile(filepath, os.O_WRONLY, 0666)
+	file, err := c.os.OpenFile(constants.TunnelDevice, os.O_WRONLY, 0666)
 	if err != nil {
 		return err
 	}
diff --git a/internal/provider/cyberghost.go b/internal/provider/cyberghost.go
index f7d935cf..7630c019 100644
--- a/internal/provider/cyberghost.go
+++ b/internal/provider/cyberghost.go
@@ -143,6 +143,6 @@ func (c *cyberghost) BuildConf(connection models.OpenVPNConnection,
 
 func (c *cyberghost) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for cyberghost")
 }
diff --git a/internal/provider/mullvad.go b/internal/provider/mullvad.go
index c01d66a9..ae943890 100644
--- a/internal/provider/mullvad.go
+++ b/internal/provider/mullvad.go
@@ -137,6 +137,6 @@ func (m *mullvad) BuildConf(connection models.OpenVPNConnection,
 
 func (m *mullvad) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for mullvad")
 }
diff --git a/internal/provider/nordvpn.go b/internal/provider/nordvpn.go
index e31496ed..5f4dad3a 100644
--- a/internal/provider/nordvpn.go
+++ b/internal/provider/nordvpn.go
@@ -28,7 +28,7 @@ func newNordvpn(servers []models.NordvpnServer, timeNow timeNowFunc) *nordvpn {
 	}
 }
 
-func (n *nordvpn) filterServers(regions []string, protocol models.NetworkProtocol, numbers []uint16) (
+func (n *nordvpn) filterServers(regions []string, protocol string, numbers []uint16) (
 	servers []models.NordvpnServer) {
 	numbersStr := make([]string, len(numbers))
 	for i := range numbers {
@@ -151,6 +151,6 @@ func (n *nordvpn) BuildConf(connection models.OpenVPNConnection,
 
 func (n *nordvpn) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for nordvpn")
 }
diff --git a/internal/provider/piav4.go b/internal/provider/piav4.go
index 0de15603..a4e7b99c 100644
--- a/internal/provider/piav4.go
+++ b/internal/provider/piav4.go
@@ -212,7 +212,7 @@ func (p *pia) BuildConf(connection models.OpenVPNConnection,
 //nolint:gocognit
 func (p *pia) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	commonName := p.activeServer.ServerName
 	if !p.activeServer.PortForward {
 		pfLogger.Error("The server %s (region %s) does not support port forwarding",
@@ -267,7 +267,7 @@ func (p *pia) PortForward(ctx context.Context, client *http.Client,
 		return
 	}
 
-	filepath := string(syncState(data.Port))
+	filepath := syncState(data.Port)
 	pfLogger.Info("Writing port to %s", filepath)
 	if err := writePortForwardedToFile(openFile, filepath, data.Port); err != nil {
 		pfLogger.Error(err)
@@ -322,7 +322,7 @@ func (p *pia) PortForward(ctx context.Context, client *http.Client,
 			}
 			filepath := syncState(data.Port)
 			pfLogger.Info("Writing port to %s", filepath)
-			if err := writePortForwardedToFile(openFile, string(filepath), data.Port); err != nil {
+			if err := writePortForwardedToFile(openFile, filepath, data.Port); err != nil {
 				pfLogger.Error(err)
 			}
 			if err := bindPIAPort(ctx, client, gateway, data); err != nil {
@@ -337,7 +337,7 @@ func (p *pia) PortForward(ctx context.Context, client *http.Client,
 	}
 }
 
-func filterPIAServers(servers []models.PIAServer, regions []string, protocol models.NetworkProtocol) (
+func filterPIAServers(servers []models.PIAServer, regions []string, protocol string) (
 	filtered []models.PIAServer) {
 	for _, server := range servers {
 		switch {
@@ -417,8 +417,7 @@ type piaPortForwardData struct {
 }
 
 func readPIAPortForwardData(openFile os.OpenFileFunc) (data piaPortForwardData, err error) {
-	const filepath = string(constants.PIAPortForward)
-	file, err := openFile(filepath, os.O_RDONLY, 0)
+	file, err := openFile(constants.PIAPortForward, os.O_RDONLY, 0)
 	if os.IsNotExist(err) {
 		return data, nil
 	} else if err != nil {
@@ -435,8 +434,7 @@ func readPIAPortForwardData(openFile os.OpenFileFunc) (data piaPortForwardData,
 }
 
 func writePIAPortForwardData(openFile os.OpenFileFunc, data piaPortForwardData) (err error) {
-	const filepath = string(constants.PIAPortForward)
-	file, err := openFile(filepath,
+	file, err := openFile(constants.PIAPortForward,
 		os.O_CREATE|os.O_TRUNC|os.O_WRONLY,
 		0644)
 	if err != nil {
@@ -518,8 +516,7 @@ func fetchPIAToken(ctx context.Context, openFile os.OpenFileFunc,
 }
 
 func getOpenvpnCredentials(openFile os.OpenFileFunc) (username, password string, err error) {
-	const filepath = string(constants.OpenVPNAuthConf)
-	file, err := openFile(filepath, os.O_RDONLY, 0)
+	file, err := openFile(constants.OpenVPNAuthConf, os.O_RDONLY, 0)
 	if err != nil {
 		return "", "", fmt.Errorf("cannot read openvpn auth file: %s", err)
 	}
diff --git a/internal/provider/privado.go b/internal/provider/privado.go
index 411e6115..12cbf151 100644
--- a/internal/provider/privado.go
+++ b/internal/provider/privado.go
@@ -128,6 +128,6 @@ func (s *privado) BuildConf(connection models.OpenVPNConnection,
 
 func (s *privado) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for privado")
 }
diff --git a/internal/provider/provider.go b/internal/provider/provider.go
index 0ae17fb2..655b6d27 100644
--- a/internal/provider/provider.go
+++ b/internal/provider/provider.go
@@ -20,10 +20,10 @@ type Provider interface {
 	BuildConf(connection models.OpenVPNConnection, username string, settings configuration.OpenVPN) (lines []string)
 	PortForward(ctx context.Context, client *http.Client,
 		openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-		syncState func(port uint16) (pfFilepath models.Filepath))
+		syncState func(port uint16) (pfFilepath string))
 }
 
-func New(provider models.VPNProvider, allServers models.AllServers, timeNow timeNowFunc) Provider {
+func New(provider string, allServers models.AllServers, timeNow timeNowFunc) Provider {
 	switch provider {
 	case constants.PrivateInternetAccess:
 		return newPrivateInternetAccess(allServers.Pia.Servers, timeNow)
diff --git a/internal/provider/purevpn.go b/internal/provider/purevpn.go
index a4b1825c..2a333f71 100644
--- a/internal/provider/purevpn.go
+++ b/internal/provider/purevpn.go
@@ -160,6 +160,6 @@ func (p *purevpn) BuildConf(connection models.OpenVPNConnection,
 
 func (p *purevpn) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for purevpn")
 }
diff --git a/internal/provider/surfshark.go b/internal/provider/surfshark.go
index 1ee29a0f..499b7b96 100644
--- a/internal/provider/surfshark.go
+++ b/internal/provider/surfshark.go
@@ -149,6 +149,6 @@ func (s *surfshark) BuildConf(connection models.OpenVPNConnection,
 
 func (s *surfshark) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for surfshark")
 }
diff --git a/internal/provider/vyprvpn.go b/internal/provider/vyprvpn.go
index 3d3fe845..b78f6ed8 100644
--- a/internal/provider/vyprvpn.go
+++ b/internal/provider/vyprvpn.go
@@ -129,6 +129,6 @@ func (v *vyprvpn) BuildConf(connection models.OpenVPNConnection,
 
 func (v *vyprvpn) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for vyprvpn")
 }
diff --git a/internal/provider/windscribe.go b/internal/provider/windscribe.go
index 8ea72862..93ffc700 100644
--- a/internal/provider/windscribe.go
+++ b/internal/provider/windscribe.go
@@ -143,6 +143,6 @@ func (w *windscribe) BuildConf(connection models.OpenVPNConnection,
 
 func (w *windscribe) PortForward(ctx context.Context, client *http.Client,
 	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,
-	syncState func(port uint16) (pfFilepath models.Filepath)) {
+	syncState func(port uint16) (pfFilepath string)) {
 	panic("port forwarding is not supported for windscribe")
 }
diff --git a/internal/publicip/loop.go b/internal/publicip/loop.go
index b2e3a60a..96cf13fc 100644
--- a/internal/publicip/loop.go
+++ b/internal/publicip/loop.go
@@ -135,7 +135,7 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 				close(errorCh)
 				filepath := l.GetSettings().IPFilepath
 				l.logger.Info("Removing ip file %s", filepath)
-				if err := l.os.Remove(string(filepath)); err != nil {
+				if err := l.os.Remove(filepath); err != nil {
 					l.logger.Error(err)
 				}
 				return
@@ -151,8 +151,8 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 				getCancel()
 				l.state.setPublicIP(ip)
 				l.logger.Info("Public IP address is %s", ip)
-				filepath := string(l.state.settings.IPFilepath)
-				err := persistPublicIP(l.os.OpenFile, filepath, ip.String(), l.puid, l.pgid)
+				err := persistPublicIP(l.os.OpenFile, l.state.settings.IPFilepath,
+					ip.String(), l.puid, l.pgid)
 				if err != nil {
 					l.logger.Error(err)
 				}