diff --git a/target/router/isolinux.cfg b/target/router/isolinux.cfg
index e61dc89d7..106af7cbe 100644
--- a/target/router/isolinux.cfg
+++ b/target/router/isolinux.cfg
@@ -1,4 +1,4 @@
-
+SERIAL 0 38400
 DEFAULT router
 
 LABEL router