diff --git a/findrefs/models.py b/findrefs/models.py
index 30aed8f..aa72f98 100644
--- a/findrefs/models.py
+++ b/findrefs/models.py
@@ -19,10 +19,11 @@
     Record,
     TracksRun,
     TracksUpdates,
+    ValidateFields,
 )
 
 
-class Reference(Record, CanValidate, TracksRun, TracksUpdates):
+class Reference(Record, CanValidate, TracksRun, TracksUpdates, ValidateFields):
     """References such as a publication or document, with unique identifiers and metadata.
 
     Example: