diff --git a/mimir/attacks/reference.py b/mimir/attacks/reference.py
index 077d05e..6ea87ec 100644
--- a/mimir/attacks/reference.py
+++ b/mimir/attacks/reference.py
@@ -19,4 +19,4 @@ def _attack(self, document, probs, tokens=None, **kwargs):
         if loss is None:
             loss = self.model.get_ll(document, probs=probs, tokens=tokens)
         ref_loss = self.ref_model.get_ll(document, probs=probs, tokens=tokens)
-        return ref_loss - loss
+        return loss - ref_loss