diff --git a/imap_filter/imap_filter.py b/imap_filter/imap_filter.py
index 461cb0c..d5e43a3 100644
--- a/imap_filter/imap_filter.py
+++ b/imap_filter/imap_filter.py
@@ -159,6 +159,8 @@ class ImapFilter:
         return True
 
     def _create_sieve_script(self, filters):
+        owner = None
+        group = None
         if os.path.exists(self.config['sieve_scripts_path']):
             self._log.debug(
                 "Updating Sieve script in '%s'...",
@@ -214,7 +216,8 @@ class ImapFilter:
         with open(self.config['sieve_scripts_path'], 'w', encoding='UTF-8') as sieve_script:
             sieve_script.write(content)
         if os.geteuid() == 0:
-            os.chown(self.config['sieve_scripts_path'], owner, group)
+            if owner and group:
+                os.chown(self.config['sieve_scripts_path'], owner, group)
         os.chmod(
             self.config['sieve_scripts_path'],
             0o777