diff --git a/libervia/backend/core/main.py b/libervia/backend/core/main.py
index 7da6aeca..c77b9129 100644
--- a/libervia/backend/core/main.py
+++ b/libervia/backend/core/main.py
@@ -105,7 +105,10 @@ class LiberviaBackend(service.Service):
         else:
             self.local_shared_path = None
 
-        defer.ensureDeferred(self._post_init())
+        # XXX: we use callLater here to be sure that the reactor is running when doing
+        #   post initialisation. This is notably important in background mode where
+        #   reactor is run later.
+        reactor.callLater(0, lambda: defer.ensureDeferred(self._post_init()))
 
     @property
     def version(self):