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 b01b8e4a8538df307c3e35e3bec332fc515753b0..951816bc8a639c13fa7a80030bca0e3be973389d 100644
--- a/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java
+++ b/oaipmh-core/src/main/java/info/textgrid/middleware/SetDeliverer.java
@@ -240,8 +240,8 @@ public class SetDeliverer {
               // Divide ID and title.
               String combined = b.getKeyAsString();
               int indexOf = combined.indexOf(DH_COLLECTION_FILTER_NAME);
-              String id = combined.substring(0, indexOf);
-              String title = combined.substring(indexOf + 1);
+              String id = combined.substring(0, indexOf - 1);
+              String title = combined.substring(indexOf);
               // Set set.
               SetType newSet = new SetType();
               newSet.setSetSpec(id);