diff --git a/libervia/backend/plugins/plugin_xep_0338.py b/libervia/backend/plugins/plugin_xep_0338.py
index f9f4855b..c0604072 100644
--- a/libervia/backend/plugins/plugin_xep_0338.py
+++ b/libervia/backend/plugins/plugin_xep_0338.py
@@ -124,8 +124,11 @@ class XEP_0338:
         media_data: dict,
         desc_elt: domish.Element,
     ) -> None:
-        jingle_elt = session["jingle_elt"]
-        self.add_group_element(jingle_elt, session)
+        if content_name == next(iter(session["contents"])):
+            # the <group> element must be added only once, so we do it only for the first
+            # content
+            jingle_elt = session["jingle_elt"]
+            self.add_group_element(jingle_elt, session)
 
     def _jingle_handler_trigger(
         self,