diff --git a/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java b/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java
index 561cb0dc76020f4b31667296eea1d92880f4100f..e0e87d70f221c9760028f2a3d40d4e79c1050f46 100644
--- a/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java
+++ b/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java
@@ -125,7 +125,7 @@ public class SetDeliverer {
     else if (this.dariah) {
 
       Script collectionID = new Script("doc['administrativeMetadata.dcterms:identifier']");
-
+      
       // Do filter all collections (via descriptiveMetadata.dc:format) AND
       // get out all the child objects and collections (NO descriptiveMetadata.dc:relation),
       // so we get exactly one set per root collection only!
@@ -137,6 +137,7 @@ public class SetDeliverer {
 
       AggregationBuilder collectionFilterTerm =
           AggregationBuilders.terms(DH_COLLECTION_FILTER_TERM_NAME)
+              .field("administrativeMetadata.dcterms:identifier")
               // .script(collectionID)
               .size(DH_SIZE);