diff --git a/plinth/modules/letsencrypt/__init__.py b/plinth/modules/letsencrypt/__init__.py
index 2b603c5a0..2763a5a51 100644
--- a/plinth/modules/letsencrypt/__init__.py
+++ b/plinth/modules/letsencrypt/__init__.py
@@ -83,6 +83,9 @@ class LetsEncryptApp(app_module.App):
                                        **manifest.backup)
         self.add(backup_restore)
 
+    @staticmethod
+    def post_init():
+        """Perform post initialization operations."""
         domain_added.connect(on_domain_added)
         domain_removed.connect(on_domain_removed)