diff -u b/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
--- b/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -40,7 +40,7 @@
  * Below this version:
  * - New sites cannot be installed, except from within tests.
  * - Updates from previous Drupal versions can be run, but users are warned
- *   that Drupal no longer supports this PHP version.
+ *   that Drupal no longer supports that PHP version.
  * - An error is shown in the status report that the PHP version is too old.
  *
  * @todo Move this to an appropriate autoloadable class. See
diff -u b/core/modules/system/system.install b/core/modules/system/system.install
--- b/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -227,13 +227,2 @@
 
-  // Suggest to update to at least 5.5.21 or 5.6.5 for disabling multiple
-  // statements.
-  if (($phase === 'install' || \Drupal::database()->driver() === 'mysql') && !SystemRequirements::phpVersionWithPdoDisallowMultipleStatements($phpversion)) {
-    $requirements['php_multiple_statement'] = [
-      'title' => t('PHP (multiple statement disabling)'),
-      'value' => $phpversion_label,
-      'description' => t('PHP versions higher than 5.6.5 or 5.5.21 provide built-in SQL injection protection for mysql databases. It is recommended to update.'),
-      'severity' => REQUIREMENT_INFO,
-    ];
-  }
-
   // Test for PHP extensions.
diff -u b/core/tests/Drupal/Tests/RequirementsPageTrait.php b/core/tests/Drupal/Tests/RequirementsPageTrait.php
--- b/core/tests/Drupal/Tests/RequirementsPageTrait.php
+++ b/core/tests/Drupal/Tests/RequirementsPageTrait.php
@@ -23,6 +23,10 @@
   /**
    * Continues installation when the expected warnings are found.
    *
+   * This function is no longer called by any core test, but it is retained for
+   * use by contrib/custom tests. It is not deprecated, because it remains the
+   * recommended function to call for its purpose.
+   *
    * @param string[] $expected_warnings
    *   A list of warning summaries to expect on the requirements screen (e.g.
    *   'PHP', 'PHP OPcode caching', etc.). If only the expected warnings