diff --git a/graphviz_noderef.module b/graphviz_noderef.module
index 45a1052..7d7be57 100644
--- a/graphviz_noderef.module
+++ b/graphviz_noderef.module
@@ -632,7 +632,7 @@ function graphviz_noderef_get_node_refs($node){
 	$ref_field = $node->$field_name;
 	foreach ($ref_field[0]['items'] as $referrer) {
 	  $nids_to_check[] = $referrer['nid'];
-	  foreach ($referrer['referrers'] as $referrername) {
+    	  if  ( (int)($referrer['nid']) != 0 ) {
 	    $referrers[] = array('nid' => $node->nid, 'type' => $field['type'], 'field' => $field_name, 'ref' => (int)$referrer['nid'], 'referrer' => $referrername, 'label'=> $field['label']);
 	  }
 	}