diff --git a/store/ARC2_StoreEndpoint.php b/store/ARC2_StoreEndpoint.php
index 864f80af..0dea2933 100755
--- a/store/ARC2_StoreEndpoint.php
+++ b/store/ARC2_StoreEndpoint.php
@@ -429,13 +429,13 @@ public function getSPARQLJSONSelectResultDoc($r)
                     $r .= '        "'.$var.'": {';
                     if ('uri' == $row[$var.' type']) {
                         $r .= $nl.'          "type": "uri",';
-                        $r .= $nl.'          "value": "'.$this->store->a['db_object']->escape($row[$var]).'"';
+                        $r .= $nl.'          "value": "'.$this->a['db_object']->escape($row[$var]).'"';
                     } elseif ('bnode' == $row[$var.' type']) {
                         $r .= $nl.'          "type": "bnode",';
                         $r .= $nl.'          "value": "'.substr($row[$var], 2).'"';
                     } else {
-                        $dt = isset($row[$var.' datatype']) ? ','.$nl.'          "datatype": "'.$this->store->a['db_object']->escape($row[$var.' datatype']).'"' : '';
-                        $lang = isset($row[$var.' lang']) ? ','.$nl.'          "xml:lang": "'.$this->store->a['db_object']->escape($row[$var.' lang']).'"' : '';
+                        $dt = isset($row[$var.' datatype']) ? ','.$nl.'          "datatype": "'.$this->a['db_object']->escape($row[$var.' datatype']).'"' : '';
+                        $lang = isset($row[$var.' lang']) ? ','.$nl.'          "xml:lang": "'.$this->a['db_object']->escape($row[$var.' lang']).'"' : '';
                         $type = $dt ? 'typed-literal' : 'literal';
                         $r .= $nl.'          "type": "'.$type.'",';
                         $r .= $nl.'          "value": "'.$this->jsonEscape($row[$var]).'"';
diff --git a/tests/unit/store/ARC2_StoreEndpointTest.php b/tests/unit/store/ARC2_StoreEndpointTest.php
new file mode 100644
index 00000000..471199d4
--- /dev/null
+++ b/tests/unit/store/ARC2_StoreEndpointTest.php
@@ -0,0 +1,67 @@
+<?php
+
+namespace Tests\unit\store;
+
+use Tests\ARC2_TestCase;
+
+
+//Tests ARC2_StoreEndpoint functions  
+class ARC2_StoreEndpointTest extends ARC2_TestCase
+{
+
+    public function setUp(): void
+    {
+        parent::setUp();
+        $this->endpoint = \ARC2::getStoreEndpoint($this->dbConfig);
+        $this->endpoint->createDBCon();
+    }
+    public function testJSON()
+    {
+
+        $data = array(
+            'result' => array(
+                'variables' => array(
+                    'a',
+                    'b',
+                    'c'
+                ),
+                'rows' => array(
+                    array(
+                        'a' => 'http://de.dbpedia.org/resource/Johann_von_Pont',
+                        'a type' => 'uri',
+                        'b' => 'http://dbpedia.org/ontology/deathPlace',
+                        'b type' => 'uri',
+                        'c' => 'http://de.dbpedia.org/resource/Aachen',
+                        'c type' => 'uri'
+                    ),
+                    array(
+                        'a' => 'http://de.dbpedia.org/resource/Aachen',
+                        'a type' => 'uri',
+                        'b' => 'http://dbpedia.org/ontology/elevation',
+                        'b type' => 'uri',
+                        'c' => '173.0',
+                        'c type' => 'literal',
+                        'c datatype' => 'http://www.w3.org/2001/XMLSchema#double'
+                    ),
+                    array(
+                        'a' => 'http://de.dbpedia.org/resource/Aachen',
+                        'a type' => 'uri',
+                        'b' => 'http://dbpedia.org/ontology/leaderTitle',
+                        'b type' => 'uri',
+                        'c' => 'Oberbürgermeister',
+                        'c type' => 'literal',
+                        'c lang' => 'de'
+                    )
+                )
+            ),
+            'query_time' => 1
+        );
+        $res  = json_decode($this->endpoint->getSPARQLJSONSelectResultDoc($data), true);
+        $this->assertArrayHasKey('head', $res);
+        $this->assertArrayHasKey('results', $res);
+        $this->assertEquals($res['head']['vars'][0], 'a');
+        $this->assertEquals($res['results']['bindings'][0]['a']['value'], 'http://de.dbpedia.org/resource/Johann_von_Pont');
+        $this->assertEquals($res['results']['bindings'][1]['c']['type'], 'typed-literal');
+        $this->assertEquals($res['results']['bindings'][2]['c']['type'], 'literal');
+    }
+}