diff --git a/xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/objects/BaseCollection.java b/xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/objects/BaseCollection.java
index 37fa42e353b78630e6ec1ca473251f0b9df22f89..465d6b9c93044335629bd03d61ad396be24608c1 100644
--- a/xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/objects/BaseCollection.java
+++ b/xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/objects/BaseCollection.java
@@ -192,7 +192,7 @@ public void setXClassReference(EntityReference xClassReference)
         EntityReference ref = xClassReference;
 
         if (ref != null) {
-            WikiReference wiki = (WikiReference) xClassReference.extractReference(EntityType.WIKI);
+            EntityReference wiki = xClassReference.extractReference(EntityType.WIKI);
             if (wiki != null) {
                 ref = xClassReference.removeParent(wiki);