diff --git a/connections/implementation/proto/offline_wire_formats.proto b/connections/implementation/proto/offline_wire_formats.proto
index 106b4854..d4e2fed0 100644
--- a/connections/implementation/proto/offline_wire_formats.proto
+++ b/connections/implementation/proto/offline_wire_formats.proto
@@ -426,6 +426,7 @@ message AutoReconnectFrame {
   }
   optional string endpoint_id = 1;
   optional EventType event_type = 2;
+  optional string last_endpoint_id = 3;
 }
 
 message MediumMetadata {