diff --git a/include/wb/Claims.php b/include/wb/Claims.php
index 3cdfd0d..3f3aaf6 100644
--- a/include/wb/Claims.php
+++ b/include/wb/Claims.php
@@ -1,139 +1,140 @@
 <?php
 # Boz-MW - Another MediaWiki API handler in PHP
-# Copyright (C) 2017, 2018 Valerio Bozzolan
+# Copyright (C) 2017-2023 Valerio Bozzolan, contributors
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 # Wikibase
 namespace wb;
 
 /**
  * Claim collector
  */
 class Claims {
 
 	/**
 	 * All the claims
 	 *
 	 * @TODO: check if it can be declared as private without breaking casts :^)
 	 * @var array
 	 */
 	public $claims = [];
 
 	/**
 	 * Constructor
 	 *
 	 * @param $claims array
 	 */
 	public function __construct( $claims = [] ) {
 		foreach( $claims as $claim ) {
 			$this->add( $claim );
 		}
 	}
 
 	/**
 	 * Add a claim
 	 *
 	 * @param $claim $Claim
 	 * @return self
 	 */
 	public function add( Claim $claim ) {
 		$this->claims[] = $claim;
 		return $this;
 	}
 
 	/**
 	 * Count all
 	 *
 	 * @return int
 	 */
 	public function count() {
 		return count( $this->claims );
 	}
 
 	/**
 	 * Get all the claims in a certain property
 	 *
 	 * @param $property string
 	 * @return array
 	 */
 	public function getInProperty( $property ) {
 		$claims = [];
 		foreach( $this->claims as $claim ) {
 			if( $claim->getMainSnak()->getProperty() === $property ) {
 				$claims[] = $claim;
 			}
 		}
 		return $claims;
 	}
 
 	/**
 	 * Check if there are claims in a certain property
 	 *
 	 * @param $property string
 	 * @return bool
 	 */
 	public function haveProperty( $property ) {
 		foreach( $this->claims as $claim ) {
 			$snak = $claim->getMainsnak();
 			if( $snak && $snak->getProperty() === $property ) {
 				return true;
 			}
 		}
 		return false;
 	}
 
 	/**
 	 * Get all the claims
 	 *
 	 * @return array
 	 */
 	public function getAll() {
 		return $this->claims;
 	}
 
 	/**
 	 * Get all the claims indexed by their property
 	 *
 	 * Note that you can obtain also a dummy property
 	 *
 	 * @return array
 	 */
 	public function getAllGrouped() {
 		$properties = [];
 		foreach( $this->getAll() as $claim ) {
 			$property = $claim->getPropertyAlsoDummy();
 			if( ! isset( $properties[ $property ] ) ) {
 				$properties[ $property ] = [];
 			}
 			$properties[ $property ][] = $claim;
 		}
 		return $properties;
 	}
 
 	/**
 	 * Convert this object to an associative array suitable for JSON encoding
 	 *
 	 * @return array
 	 */
 	public function toData() {
-		$all = $this->getAllGrouped();
-		foreach( $all as & $claims ) {
+		$data = [];
+		foreach( $this->getAllGrouped() as $prop => $claims ) {
+			$data[ $prop ] = [];
 			foreach( $claims as & $claim ) {
-				$claim = $claim->toData();
+				$data[ $prop ][] = $claim->toData();
 			}
 		}
-		return $all;
+		return $data;
 	}
 }