diff --git a/src/common/WiFiSettings/WiFiForm.js b/src/common/WiFiSettings/WiFiForm.js
index 6005d6b..63bfd47 100644
--- a/src/common/WiFiSettings/WiFiForm.js
+++ b/src/common/WiFiSettings/WiFiForm.js
@@ -105,6 +105,7 @@ function DeviceForm({
                         label="SSID"
                         value={formData.SSID}
                         error={formErrors.SSID || null}
+                        helpText={HELP_TEXTS.ssid}
                         required
                         onChange={setFormValue((value) => ({
                             devices: {
diff --git a/src/common/WiFiSettings/WiFiGuestForm.js b/src/common/WiFiSettings/WiFiGuestForm.js
index 93380cd..7ae88c0 100644
--- a/src/common/WiFiSettings/WiFiGuestForm.js
+++ b/src/common/WiFiSettings/WiFiGuestForm.js
@@ -57,6 +57,7 @@ export default function WifiGuestForm({
                         label="SSID"
                         value={formData.SSID}
                         error={formErrors.SSID}
+                        helpText={HELP_TEXTS.ssid}
                         onChange={setFormValue((value) => ({
                             devices: {
                                 [formData.id]: {
diff --git a/src/common/WiFiSettings/WiFiSettings.js b/src/common/WiFiSettings/WiFiSettings.js
index 8b55fa5..be455af 100644
--- a/src/common/WiFiSettings/WiFiSettings.js
+++ b/src/common/WiFiSettings/WiFiSettings.js
@@ -63,14 +63,10 @@ function prepDataToSubmit(formData) {
     return formData;
 }
 
-function diacriticValidation(string) {
-    for (let i = 0; i < string.length; i++) {
-        const charCode = string.charCodeAt(i);
-        if (charCode < 32 || charCode > 127) {
-            return false;
-        }
-    }
-    return true;
+export function byteCount(string) {
+    const buffer = Buffer.from(string, "utf-8");
+    const count = buffer.byteLength;
+    return count;
 }
 
 export function validator(formData) {
@@ -81,10 +77,8 @@ export function validator(formData) {
         if (device.SSID.length > 32)
             errors.SSID = _("SSID can't be longer than 32 symbols");
         if (device.SSID.length === 0) errors.SSID = _("SSID can't be empty");
-        if (!diacriticValidation(device.SSID))
-            errors.SSID = _(
-                "Your SSID contains non-standard characters. These are not forbidden, but could cause problems on some devices."
-            );
+        if (byteCount(device.SSID) > 32)
+            errors.SSID = _("SSID can't be longer than 32 bytes");
 
         if (device.password.length < 8)
             errors.password = _("Password must contain at least 8 symbols");
@@ -96,6 +90,8 @@ export function validator(formData) {
             guest_wifi_errors.SSID = _("SSID can't be longer than 32 symbols");
         if (device.guest_wifi.SSID.length === 0)
             guest_wifi_errors.SSID = _("SSID can't be empty");
+        if (byteCount(device.guest_wifi.SSID) > 32)
+            guest_wifi_errors.SSID = _("SSID can't be longer than 32 bytes");
 
         if (device.guest_wifi.password.length < 8)
             guest_wifi_errors.password = _(
diff --git a/src/common/WiFiSettings/constants.js b/src/common/WiFiSettings/constants.js
index 480c505..0018fef 100644
--- a/src/common/WiFiSettings/constants.js
+++ b/src/common/WiFiSettings/constants.js
@@ -19,6 +19,9 @@ export const HWMODES = {
     "11a": "5",
 };
 export const HELP_TEXTS = {
+    ssid: _(
+        `SSID which contains non-standard characters could cause problems on some devices.`
+    ),
     password: _(`
         WPA2 pre-shared key, that is required to connect to the network.
     `),