diff --git a/internal/configuration/settings/helpers/messages.go b/internal/configuration/settings/helpers/messages.go
deleted file mode 100644
index 1442b979..00000000
--- a/internal/configuration/settings/helpers/messages.go
+++ /dev/null
@@ -1,29 +0,0 @@
-package helpers
-
-import (
-	"fmt"
-	"strings"
-)
-
-func ChoicesOrString(choices []string) string {
-	return strings.Join(
-		choices[:len(choices)-1], ", ") +
-		" or " + choices[len(choices)-1]
-}
-
-func PortChoicesOrString(ports []uint16) (s string) {
-	switch len(ports) {
-	case 0:
-		return "there is no allowed port"
-	case 1:
-		return "allowed port is " + fmt.Sprint(ports[0])
-	}
-
-	s = "allowed ports are "
-	portStrings := make([]string, len(ports))
-	for i := range ports {
-		portStrings[i] = fmt.Sprint(ports[i])
-	}
-	s += ChoicesOrString(portStrings)
-	return s
-}
diff --git a/internal/configuration/settings/wireguardselection.go b/internal/configuration/settings/wireguardselection.go
index b153bd73..04b8c89d 100644
--- a/internal/configuration/settings/wireguardselection.go
+++ b/internal/configuration/settings/wireguardselection.go
@@ -4,9 +4,9 @@ import (
 	"fmt"
 	"net/netip"
 
-	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gosettings"
+	"github.com/qdm12/gosettings/validate"
 	"github.com/qdm12/gotree"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 )
@@ -77,12 +77,12 @@ func (w WireguardSelection) validate(vpnProvider string) (err error) {
 			allowed = []uint16{53, 80, 123, 443, 1194, 65142}
 		}
 
-		if helpers.IsOneOf(*w.EndpointPort, allowed...) {
+		err = validate.IsOneOf(*w.EndpointPort, allowed...)
+		if err == nil {
 			break
 		}
-		return fmt.Errorf("%w: %d for VPN service provider %s; %s",
-			ErrWireguardEndpointPortNotAllowed, w.EndpointPort, vpnProvider,
-			helpers.PortChoicesOrString(allowed))
+		return fmt.Errorf("%w: for VPN service provider %s: %w",
+			ErrWireguardEndpointPortNotAllowed, vpnProvider, err)
 	default: // Providers not supporting Wireguard
 	}