diff -u b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
--- b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
+++ b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
@@ -32,7 +32,7 @@
    *
    * @see https://getcomposer.org/doc/04-schema.md#minimum-stability
    */
-  const MINIMUM_STABILITY = 'stable';
+  protected const MINIMUM_STABILITY = 'stable';
 
   /**
    * The order of stability strings from least stable to most stable.
@@ -40,7 +40,7 @@
    * This only includes normalized stability strings: i.e., ones that are
    * returned by \Composer\Semver\VersionParser::parseStability().
    */
-  const STABILITY_ORDER = ['dev', 'alpha', 'beta', 'RC', 'stable'];
+  protected const STABILITY_ORDER = ['dev', 'alpha', 'beta', 'RC', 'stable'];
 
   /**
    * Get Composer items that we want to be path repos, from within a directory.
@@ -157,7 +157,7 @@
     // running them on a tagged release at the same stability as specified in
     // static::MINIMUM_STABILITY, in order to verify that everything will work
     // if/when we make such a release.
-    $simulated_core_version = \Drupal::VERSION_FLOOR;
+    $simulated_core_version = \Drupal::VERSION;
     $simulated_core_version_suffix = (static::MINIMUM_STABILITY === 'stable' ? '' : '-' . static::MINIMUM_STABILITY . '99');
     $simulated_core_version = str_replace('-dev', $simulated_core_version_suffix, $simulated_core_version);
     Composer::setDrupalVersion($this->getWorkspaceDirectory(), $simulated_core_version);