diff --git a/core/modules/datetime/src/Tests/DateTimeFieldTest.php b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
index 083e630..0f2f4ff 100644
--- a/core/modules/datetime/src/Tests/DateTimeFieldTest.php
+++ b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
@@ -142,11 +142,11 @@ function testDateField() {
 
       // Test that allowed markup in custom format is preserved and XSS is
       // removed.
-      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\X\\S\\S\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
+      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\S\\t\\r\\i\\n\\g\\.\\f\\r\\o\\m\\C\\h\\a\\r\\C\\o\\d\\e\\(\\8\\8\\,\\8\\3\\,\\8\\3\\)\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
       entity_get_display($this->field->getTargetEntityTypeId(), $this->field->getTargetBundle(), 'full')
         ->setComponent($field_name, $this->displayOptions)
         ->save();
-      $expected = '<strong>' . $date->format('m/d/Y') . '</strong>alert(XSS)';
+      $expected = '<strong>' . $date->format('m/d/Y') . '</strong>alert(String.fromCharCode(88,83,83))';
       $this->renderTestEntity($id);
       $this->assertRaw($expected, new FormattableMarkup('Formatted date field using daterange_custom format displayed as %expected.', array('%expected' => $expected)));
 
diff --git a/core/modules/datetime_range/src/Tests/DateRangeFieldTest.php b/core/modules/datetime_range/src/Tests/DateRangeFieldTest.php
index c1057e0..74b8f6a 100644
--- a/core/modules/datetime_range/src/Tests/DateRangeFieldTest.php
+++ b/core/modules/datetime_range/src/Tests/DateRangeFieldTest.php
@@ -167,11 +167,11 @@ public function testDateRangeField() {
 
       // Test that allowed markup in custom format is preserved and XSS is
       // removed.
-      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\X\\S\\S\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
+      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\S\\t\\r\\i\\n\\g\\.\\f\\r\\o\\m\\C\\h\\a\\r\\C\\o\\d\\e\\(\\8\\8\\,\\8\\3\\,\\8\\3\\)\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
       entity_get_display($this->field->getTargetEntityTypeId(), $this->field->getTargetBundle(), 'full')
         ->setComponent($field_name, $this->displayOptions)
         ->save();
-      $expected = '<strong>' . $start_date->format('m/d/Y') . '</strong>alert(XSS) - <strong>' . $end_date->format('m/d/Y') . '</strong>alert(XSS)';
+      $expected = '<strong>' . $start_date->format('m/d/Y') . '</strong>alert(String.fromCharCode(88,83,83)) - <strong>' . $end_date->format('m/d/Y') . '</strong>alert(String.fromCharCode(88,83,83))';
       $this->renderTestEntity($id);
       $this->assertRaw($expected, new FormattableMarkup('Formatted date field using daterange_custom format displayed as %expected.', array('%expected' => $expected)));