diff -r 3fccf43160a7 -r 07b44a378ad8 server/src/app/Libraries/Sparql/SparqlClient.php
--- a/server/src/app/Libraries/Sparql/SparqlClient.php	Wed Sep 28 17:24:02 2016 +0200
+++ b/server/src/app/Libraries/Sparql/SparqlClient.php	Fri Sep 30 00:43:04 2016 +0200
@@ -128,7 +128,7 @@
         return $this->updateData('DELETE', $graph);
     }
 
-    public function deleteWhere($whereClauses, string $graphUri = null) {
+    public function deleteWhere($whereClauses, $graphUri = null) {
 
         if(empty($whereClauses)) {
             return;