diff -r 706f10bcdc3c -r f5690d918358 server/src/app/Libraries/Sparql/SparqlClient.php
--- a/server/src/app/Libraries/Sparql/SparqlClient.php	Sun Oct 02 19:11:06 2016 +0200
+++ b/server/src/app/Libraries/Sparql/SparqlClient.php	Sun Oct 02 19:14:07 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;