diff --git a/addons/event/event_view.xml b/addons/event/event_view.xml
index f58a948fad2..b1555ea7dc5 100644
--- a/addons/event/event_view.xml
+++ b/addons/event/event_view.xml
@@ -264,7 +264,7 @@
             res_model="event.registration"
             src_model="event.event"
             view_mode="tree,form,calendar,graph"
-            context="{'search_default_event_id': [active_id]}"
+            context="{'search_default_event_id': active_id}"
             view_type="form"/>
 
       <act_window