diff --git a/client/src/__locales/en.json b/client/src/__locales/en.json
index 59fa9e75..8cd51ec5 100644
--- a/client/src/__locales/en.json
+++ b/client/src/__locales/en.json
@@ -241,6 +241,7 @@
     "topline_expiring_certificate": "Your SSL certificate is about to expire. Update <0>Encryption settings</0>.",
     "topline_expired_certificate": "Your SSL certificate is expired. Update <0>Encryption settings</0>.",
     "form_error_port_range": "Enter port value in the range of 80-65535",
+    "form_error_port_unsafe": "This is an unsafe port",
     "form_error_equal": "Shouldn't be equal",
     "form_error_password": "Password mismatched",
     "reset_settings": "Reset settings"
diff --git a/client/src/components/Settings/Encryption/Form.js b/client/src/components/Settings/Encryption/Form.js
index 0ed6fffb..ac0e0577 100644
--- a/client/src/components/Settings/Encryption/Form.js
+++ b/client/src/components/Settings/Encryption/Form.js
@@ -6,7 +6,7 @@ import { Trans, withNamespaces } from 'react-i18next';
 import flow from 'lodash/flow';
 import format from 'date-fns/format';
 
-import { renderField, renderSelectField, toNumber, port } from '../../../helpers/form';
+import { renderField, renderSelectField, toNumber, port, isSafePort } from '../../../helpers/form';
 import { EMPTY_DATE } from '../../../helpers/constants';
 import i18n from '../../../i18n';
 
@@ -129,7 +129,7 @@ let Form = (props) => {
                             type="number"
                             className="form-control"
                             placeholder={t('encryption_https')}
-                            validate={[port]}
+                            validate={[port, isSafePort]}
                             normalize={toNumber}
                             onChange={handleChange}
                             disabled={!isEnabled}
diff --git a/client/src/helpers/constants.js b/client/src/helpers/constants.js
index 7c425b86..74a39a8f 100644
--- a/client/src/helpers/constants.js
+++ b/client/src/helpers/constants.js
@@ -74,3 +74,70 @@ export const SETTINGS_NAMES = {
 export const STANDARD_DNS_PORT = 53;
 export const STANDARD_WEB_PORT = 80;
 export const EMPTY_DATE = '0001-01-01T00:00:00Z';
+
+export const UNSAFE_PORTS = [
+    1,
+    7,
+    9,
+    11,
+    13,
+    15,
+    17,
+    19,
+    20,
+    21,
+    22,
+    23,
+    25,
+    37,
+    42,
+    43,
+    53,
+    77,
+    79,
+    87,
+    95,
+    101,
+    102,
+    103,
+    104,
+    109,
+    110,
+    111,
+    113,
+    115,
+    117,
+    119,
+    123,
+    135,
+    139,
+    143,
+    179,
+    389,
+    465,
+    512,
+    513,
+    514,
+    515,
+    526,
+    530,
+    531,
+    532,
+    540,
+    556,
+    563,
+    587,
+    601,
+    636,
+    993,
+    995,
+    2049,
+    3659,
+    4045,
+    6000,
+    6665,
+    6666,
+    6667,
+    6668,
+    6669,
+];
diff --git a/client/src/helpers/form.js b/client/src/helpers/form.js
index 39855671..58d11ba8 100644
--- a/client/src/helpers/form.js
+++ b/client/src/helpers/form.js
@@ -1,7 +1,7 @@
 import React, { Fragment } from 'react';
 import { Trans } from 'react-i18next';
 
-import { R_IPV4 } from '../helpers/constants';
+import { R_IPV4, UNSAFE_PORTS } from '../helpers/constants';
 
 export const renderField = ({
     input, id, className, placeholder, type, disabled, meta: { touched, error },
@@ -69,4 +69,11 @@ export const port = (value) => {
     return false;
 };
 
+export const isSafePort = (value) => {
+    if (UNSAFE_PORTS.includes(value)) {
+        return <Trans>form_error_port_unsafe</Trans>;
+    }
+    return false;
+};
+
 export const toNumber = value => value && parseInt(value, 10);