diff --git a/includes/core-phpunit/includes/abstract-testcase.php b/includes/core-phpunit/includes/abstract-testcase.php
index 1e448598e..9fa777354 100644
--- a/includes/core-phpunit/includes/abstract-testcase.php
+++ b/includes/core-phpunit/includes/abstract-testcase.php
@@ -71,8 +71,10 @@ public static function set_up_before_class() {
 
 		$wpdb->suppress_errors = false;
 		$wpdb->show_errors     = true;
-		$wpdb->db_connect();
-		ini_set( 'display_errors', 1 );
+        if ( ! $wpdb->check_connection() ) {
+            $wpdb->db_connect();
+        }
+        ini_set( 'display_errors', 1 );
 
 		$class = self::$calledClass ?? get_called_class();