diff --git a/common/plugins/eu.esdihumboldt.hale.common.instance.graph/src/eu/esdihumboldt/hale/common/instance/graph/reference/ReferenceGraph.java b/common/plugins/eu.esdihumboldt.hale.common.instance.graph/src/eu/esdihumboldt/hale/common/instance/graph/reference/ReferenceGraph.java
index 29a48db07b..1fba2d9941 100644
--- a/common/plugins/eu.esdihumboldt.hale.common.instance.graph/src/eu/esdihumboldt/hale/common/instance/graph/reference/ReferenceGraph.java
+++ b/common/plugins/eu.esdihumboldt.hale.common.instance.graph/src/eu/esdihumboldt/hale/common/instance/graph/reference/ReferenceGraph.java
@@ -242,10 +242,8 @@ public Boolean compute(LoopBundle<Vertex> loop) {
 						result.add(ref);
 					}
 					else if (!vtx.getId().equals(associated.getId())) {
-						Iterable<Vertex> referers = associated.getVertices(Direction.IN);
 						Set<String> ids = new HashSet<>();
-
-						for (Vertex referer : referers) {
+						for (Vertex referer : associated.getVertices(Direction.IN)) {
 							Object ident = referer.getId();
 							if (ident != null) {
 								ids.add(ident.toString());