diff --git a/bridgev2/networkinterface.go b/bridgev2/networkinterface.go
index 78da4b0c..a5dafe1d 100644
--- a/bridgev2/networkinterface.go
+++ b/bridgev2/networkinterface.go
@@ -1049,7 +1049,8 @@ type WebPushConfig struct {
 }
 
 type FCMPushConfig struct {
-	SenderID string `json:"sender_id"`
+	SenderID  string          `json:"sender_id"`
+	LegacyIID json.RawMessage `json:"legacy_iid,omitempty"`
 }
 
 type APNsPushConfig struct {