diff --git a/generic/models.py b/generic/models.py
index 39aa30a7..22afb54c 100644
--- a/generic/models.py
+++ b/generic/models.py
@@ -192,7 +192,7 @@ class CidUser(models.Model):
     passcode = models.CharField(blank=True, max_length=50)
 
     def __str__(self) -> str:
-        return self.cid
+        return str(self.cid)
 
 class CidUserExam(models.Model):
     content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)