diff -u b/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php b/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php
--- b/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php
+++ b/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Database\DatabaseNotFoundException;
 use Drupal\Core\Database\StatementInterface;
 
+use Locale;
 use PDO;
 use PDOException;