diff --git a/cas.install b/cas.install
index af33aba..6d822a5 100644
--- a/cas.install
+++ b/cas.install
@@ -128,3 +128,13 @@ function cas_update_8003() {
   $config->set('user_accounts.prevent_normal_login', FALSE);
   $config->save();
 }
+
+/**
+ * Set new 'protocol' config option to HTTPS.
+ */
+function cas_update_8004() {
+  $config_factory = \Drupal::configFactory();
+  $config = $config_factory->getEditable('cas.settings');
+  $config->set('server.protocol', 'https');
+  $config->save();
+}
diff --git a/src/Form/CasSettings.php b/src/Form/CasSettings.php
index 47884f2..c8ad8e1 100755
--- a/src/Form/CasSettings.php
+++ b/src/Form/CasSettings.php
@@ -79,7 +79,7 @@ class CasSettings extends ConfigFormBase {
     );
     $form['server']['version'] = array(
       '#type' => 'radios',
-      '#title' => $this->t('Protocol version'),
+      '#title' => $this->t('CAS Protocol version'),
       '#options' => array(
         '1.0' => $this->t('1.0'),
         '2.0' => $this->t('2.0'),
@@ -89,14 +89,14 @@ class CasSettings extends ConfigFormBase {
       '#description' => $this->t('The CAS protocol version your CAS server supports.'),
     );
     $form['server']['protocol'] = array(
-      '#type' => 'select',
-      '#title' => $this->t('Protocol'),
+      '#type' => 'radios',
+      '#title' => $this->t('HTTP Protocol'),
       '#options' => array(
-        'http' => $this->t('Http'),
-        'https' => $this->t('Https'),
+        'http' => $this->t('HTTP (non-secure)'),
+        'https' => $this->t('HTTPS (secure)'),
       ),
       '#default_value' => $config->get('server.protocol'),
-      '#description' => $this->t('Protocol of the CAS server. WARNING: Do not use HTTP on production environments as it can lead to security problems.'),
+      '#description' => $this->t('HTTP protocol of the CAS server. WARNING: Do not use HTTP on production environments!'),
     );
     $form['server']['hostname'] = array(
       '#type' => 'textfield',
diff --git a/src/Service/CasHelper.php b/src/Service/CasHelper.php
index 47cbb0e..9d2fbfd 100644
--- a/src/Service/CasHelper.php
+++ b/src/Service/CasHelper.php
@@ -122,11 +122,15 @@ class CasHelper {
    *   The base URL.
    */
   public function getServerBaseUrl() {
-    $url = $this->settings->get('server.protocol') . '://' . $this->settings->get('server.hostname');
+    $protocol = $this->settings->get('server.protocol');
+    $url = $protocol . '://' . $this->settings->get('server.hostname');
+
+    // Only append port if it's non standard.
     $port = $this->settings->get('server.port');
-    if (!empty($port) && $port != 443) {
+    if (($protocol == 'http' && $port != 80) || ($protocol == 'https' && $port != 443)) {
       $url .= ':' . $this->settings->get('server.port');
     }
+
     $url .= $this->settings->get('server.path');
     $url = rtrim($url, '/') . '/';
 
diff --git a/tests/src/Unit/Service/CasHelperTest.php b/tests/src/Unit/Service/CasHelperTest.php
index bc4ba66..3e9d588 100644
--- a/tests/src/Unit/Service/CasHelperTest.php
+++ b/tests/src/Unit/Service/CasHelperTest.php
@@ -126,13 +126,13 @@ class CasHelperTest extends UnitTestCase {
    * @covers ::getServerBaseUrl
    * @covers ::__construct
    */
-  public function testGetServerBaseUrlNonStandardProtocol() {
+  public function testGetServerBaseUrlNonStandardHttpProtocol() {
     /** @var \Drupal\Core\Config\ConfigFactory $config_factory */
     $config_factory = $this->getConfigFactoryStub(array(
       'cas.settings' => array(
         'server.protocol' => 'http',
         'server.hostname' => 'example.com',
-        'server.port' => 443,
+        'server.port' => 80,
         'server.path' => '/cas',
       ),
     ));