diff --git a/core/legacy/dbobjectsearchlegacy.class.php b/core/legacy/dbobjectsearchlegacy.class.php
index cad9864c1..0b361c8aa 100644
--- a/core/legacy/dbobjectsearchlegacy.class.php
+++ b/core/legacy/dbobjectsearchlegacy.class.php
@@ -52,7 +52,12 @@ class DBObjectSearch extends DBSearch
 	protected $m_bAllowAllData = false;
 	protected $m_bDataFiltered = false;
 
-    /**
+	public function ToJSON()
+	{
+		return '{}';
+	}
+
+	/**
      * DBObjectSearch constructor.
      *
      * @api
diff --git a/core/oql/expression.class.inc.php b/core/oql/expression.class.inc.php
index 3e9e4237e..20f28f353 100644
--- a/core/oql/expression.class.inc.php
+++ b/core/oql/expression.class.inc.php
@@ -27,15 +27,15 @@ class MissingQueryArgument extends CoreException
  */
 abstract class Expression
 {
-	public const OPERATOR_BINARY = 'binary';
-	public const OPERATOR_BOOLEAN = 'boolean_binary';
-	public const OPERATOR_FIELD = 'field';
-	public const OPERATOR_FUNCTION = 'function';
-	public const OPERATOR_INTERVAL = 'interval';
-	public const OPERATOR_LIST = 'list';
-	public const OPERATOR_SCALAR = 'scalar';
-	public const OPERATOR_UNARY = 'unary';
-	public const OPERATOR_VARIABLE = 'variable';
+	const OPERATOR_BINARY = 'binary';
+	const OPERATOR_BOOLEAN = 'boolean_binary';
+	const OPERATOR_FIELD = 'field';
+	const OPERATOR_FUNCTION = 'function';
+	const OPERATOR_INTERVAL = 'interval';
+	const OPERATOR_LIST = 'list';
+	const OPERATOR_SCALAR = 'scalar';
+	const OPERATOR_UNARY = 'unary';
+	const OPERATOR_VARIABLE = 'variable';
 
 
 	/**