diff --git a/scripts/setup-seafile-mysql.py b/scripts/setup-seafile-mysql.py
index 9d7bfc1775..176cbb07c1 100644
--- a/scripts/setup-seafile-mysql.py
+++ b/scripts/setup-seafile-mysql.py
@@ -973,7 +973,7 @@ class SeafileConfigurator(AbstractConfigurator):
             Utils.get_python_executable(),
             script,
         ]
-        jwt_private_key = Utils.get_command_output(cmd).strip()
+        jwt_private_key = Utils.get_command_output(cmd).strip().decode('utf8').replace('%', '')
 
         db_section = 'notification'
         if not config.has_section(db_section):