diff --git a/seahub/two_factor/models/static.py b/seahub/two_factor/models/static.py
index 19f898e70c..0c3193f8f9 100644
--- a/seahub/two_factor/models/static.py
+++ b/seahub/two_factor/models/static.py
@@ -70,4 +70,4 @@ class StaticToken(models.Model):
 
         :rtype: str
         """
-        return b32encode(urandom(5)).lower()
+        return b32encode(urandom(5)).lower().decode()