diff -u b/core/lib/Drupal/Core/Database/Database.php b/core/lib/Drupal/Core/Database/Database.php
--- b/core/lib/Drupal/Core/Database/Database.php
+++ b/core/lib/Drupal/Core/Database/Database.php
@@ -332,7 +332,8 @@
    */
   final public static function addConnectionInfo($key, $target, array $info, $class_loader = NULL) {
     if (empty(self::$databaseInfo[$key][$target])) {
-      self::$databaseInfo[$key][$target] = self::parseConnectionInfo($info);
+      $info = self::parseConnectionInfo($info);
+      self::$databaseInfo[$key][$target] = $info;
 
       // The database driver needs to be loadable before module namespaces have
       // been added to the autoloader, because the list of enabled modules and