diff --git a/modoboa/core/models.py b/modoboa/core/models.py
index dc13b0d3a..5b86c2d6d 100644
--- a/modoboa/core/models.py
+++ b/modoboa/core/models.py
@@ -456,8 +456,9 @@ class LocalConfig(models.Model):
 
     def __init__(self, *args, **kwargs):
         """Load parameter manager."""
-        super(LocalConfig, self).__init__(*args, **kwargs)
-        self.parameters = param_tools.Manager("global", self._parameters)
+        super().__init__(*args, **kwargs)
+        if self.pk:
+            self.parameters = param_tools.Manager("global", self._parameters)
 
 
 class ExtensionUpdateHistory(models.Model):
diff --git a/requirements.txt b/requirements.txt
index 9ec12d424..abf49d47a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -27,7 +27,7 @@ python-dateutil
 cryptography
 pytz
 requests
-lxml
+lxml==4.9.4  # FIXME: issue with version 5+
 chardet
 ovh
 oath