diff --git a/longs/models.py b/longs/models.py
index c2bba76e..b35acd4c 100644
--- a/longs/models.py
+++ b/longs/models.py
@@ -771,7 +771,7 @@ class CidUserAnswer(models.Model):
         mark_objects = self.mark.all()
         if not mark_objects:
             return "Unmarked"
-        markers = ",".join([i.marker for i in mark_objects])
+        markers = ",".join([str(i.marker) for i in mark_objects])
         return f"Marked by {markers}"
 
     def get_answer_score(self):