diff --git a/combo/predict.py b/combo/predict.py
index 8d6b51ffb4adf1e0f87ec61022a7a7abc7ad8407..1eba4b4ae9f613c2ffdb792737889a9958ed2f20 100644
--- a/combo/predict.py
+++ b/combo/predict.py
@@ -150,7 +150,7 @@ class COMBO(PredictorModule):
         if self.without_sentence_embedding:
             outputs.sentence_embedding = []
         if self.line_to_conllu:
-            return sentence2conllu(outputs, keep_semrel=self.dataset_reader.use_sem).serialize()
+            return sentence2conllu(outputs, keep_semrel=getattr(self.dataset_reader, 'use_sem', False)).serialize()
         else:
             return outputs.to_json()