diff --git a/core/modules/datetime/src/Tests/DateTimeFieldTest.php b/core/modules/datetime/src/Tests/DateTimeFieldTest.php
index a2cf49b..4add15f 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\\ \\s\\r\\c\\=\\"\\a\\l\\e\\r\\t\\(\\\'\\s\\o\\m\\e\\ \\x\\s\\s\\\'\\)\\;\\" \\/\\>';
+      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\"\\X\\S\\S\\"\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
       entity_get_display($this->field->getTargetEntityTypeId(), $this->field->getTargetBundle(), 'full')
         ->setComponent($field_name, $this->displayOptions)
         ->save();
-      $expected = '<strong>' . $date->format('m/d/Y') . '</strong>';
+      $expected = '<strong>' . $date->format('m/d/Y') . '</strong>alert("XSS")';
       $this->renderTestEntity($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 a2d7b19..319fdbd 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\\ \\s\\r\\c\\=\\"\\a\\l\\e\\r\\t\\(\\\'\\s\\o\\m\\e\\ \\x\\s\\s\\\'\\)\\;\\" \\/\\>';
+      $this->displayOptions['settings']['date_format'] = '\\<\\s\\t\\r\\o\\n\\g\\>m/d/Y\\<\\/\\s\\t\\r\\o\\n\\g\\>\\<\\s\\c\\r\\i\\p\\t\\>\\a\\l\\e\\r\\t\\(\\"\\X\\S\\S\\"\\)\\<\\/\\s\\c\\r\\i\\p\\t\\>';
       entity_get_display($this->field->getTargetEntityTypeId(), $this->field->getTargetBundle(), 'full')
         ->setComponent($field_name, $this->displayOptions)
         ->save();
-      $expected = '<strong>' . $start_date->format('m/d/Y') . '</strong> - <strong>' . $end_date->format('m/d/Y') . '</strong>';
+      $expected = '<strong>' . $start_date->format('m/d/Y') . '</strong>alert("XSS") - <strong>' . $end_date->format('m/d/Y') . '</strong>alert("XSS")';
       $this->renderTestEntity($id);
       $this->assertRaw($expected, new FormattableMarkup('Formatted date field using daterange_custom format displayed as %expected.', array('%expected' => $expected)));