diff --git a/core/modules/filter/filter.module b/core/modules/filter/filter.module
index ea98965..e801881 100644
--- a/core/modules/filter/filter.module
+++ b/core/modules/filter/filter.module
@@ -1390,7 +1390,7 @@ function _filter_html_image_secure_process($text) {
     // Remove absolute URLs pointing to the local domain to prevent mixed
     // content errors.
     $request = \Drupal::request();
-    $image->setAttribute('src', preg_replace('|^https?://' . $request->getHost() . '|', '', $src));
+    $image->setAttribute('src', preg_replace('|^https?://' . $request->getHttpHost() . '|', '', $src));
 
     // Verify that $src starts with $base_path.
     // This also ensures that external images cannot be referenced.
diff --git a/core/modules/filter/lib/Drupal/filter/Tests/FilterHtmlImageSecureTest.php b/core/modules/filter/lib/Drupal/filter/Tests/FilterHtmlImageSecureTest.php
index 57d9912..81a0851 100644
--- a/core/modules/filter/lib/Drupal/filter/Tests/FilterHtmlImageSecureTest.php
+++ b/core/modules/filter/lib/Drupal/filter/Tests/FilterHtmlImageSecureTest.php
@@ -97,9 +97,16 @@ function testImageSource() {
     // Create a list of test image sources.
     // The keys become the value of the IMG 'src' attribute, the values are the
     // expected filter conversions.
+    $host = $this->container->get('request')->getHost();
+    $host_pattern = '|^http\://' . $host . '(\:[0-9]{0,5})|';
     $images = array(
       $http_base_url . '/' . $druplicon => base_path() . $druplicon,
       $https_base_url . '/' . $druplicon => base_path() . $druplicon,
+      // Test a url that includes a port.
+      preg_replace($host_pattern, 'http://' . $host . ':', $http_base_url . '/' . $druplicon) => base_path() . $druplicon,
+      preg_replace($host_pattern, 'http://' . $host . ':80', $http_base_url . '/' . $druplicon) => base_path() . $druplicon,
+      preg_replace($host_pattern, 'http://' . $host . ':443', $http_base_url . '/' . $druplicon) => base_path() . $druplicon,
+      preg_replace($host_pattern, 'http://' . $host . ':8080', $http_base_url . '/' . $druplicon) => base_path() . $druplicon,
       base_path() . $druplicon => base_path() . $druplicon,
       $files_path . '/' . $test_image => $files_path . '/' . $test_image,
       $http_base_url . '/' . $public_files_path . '/' . $test_image => $files_path . '/' . $test_image,