diff --git a/plugins/radicale_openauth/__init__.py b/plugins/radicale_openauth/__init__.py
index 78b6733..581cb35 100644
--- a/plugins/radicale_openauth/__init__.py
+++ b/plugins/radicale_openauth/__init__.py
@@ -19,7 +19,7 @@ class Auth(BaseAuth):
         if "error" in data1:
             return False
 
-        salt = data1["salt"]
+        salt = data1["salt"].encode()
 
         id = self.configuration.get("auth", "client_id")
         secret = self.configuration.get("auth", "client_secret")