diff --git a/src/Form/Type/DataSourceJsonType.php b/src/Form/Type/DataSourceJsonType.php
index 7d067b41..6d11058a 100644
--- a/src/Form/Type/DataSourceJsonType.php
+++ b/src/Form/Type/DataSourceJsonType.php
@@ -95,7 +95,7 @@ class DataSourceJsonType extends AbstractType
      * @param string $json
      * @return bool
      */
-    private static function isValidJson(string $json): bool
+    public static function isValidJson(string $json): bool
     {
         json_decode($json);
         return json_last_error() === JSON_ERROR_NONE;