diff --git a/lib/src/visitor/serialize.dart b/lib/src/visitor/serialize.dart
index 676d0e69..f9c468aa 100644
--- a/lib/src/visitor/serialize.dart
+++ b/lib/src/visitor/serialize.dart
@@ -537,6 +537,7 @@ class _SerializeCssVisitor
         case $enq:
         case $ack:
         case $bel:
+        case $bs:
         case $lf:
         case $vt:
         case $ff: