Use covariant return type

1 files changed, 1 insertions, 1 deletions

diff --git a/document/src/main/java/com/yahoo/document/datatypes/ReferenceFieldValue.java b/document/src/main/java/com/yahoo/document/datatypes/ReferenceFieldValue.java
index 459681d52ae..1e4079dd3fe 100644
--- a/document/src/main/java/com/yahoo/document/datatypes/ReferenceFieldValue.java
+++ b/document/src/main/java/com/yahoo/document/datatypes/ReferenceFieldValue.java
@@ -159,7 +159,7 @@ public class ReferenceFieldValue extends FieldValue {
      * @return reference DocumentId, or null if none has been set
      */
     @Override
-    public Object getWrappedValue() {
+    public DocumentId getWrappedValue() {
         return documentId.orElse(null);
     }
 }