diff --git a/web_atoms/local_names.txt b/web_atoms/local_names.txt
index 77859eaa..466cbbbb 100644
--- a/web_atoms/local_names.txt
+++ b/web_atoms/local_names.txt
@@ -180,6 +180,7 @@ clip-rule
 clipPath
 clipPathUnits
 close
+closedby
 closure
 cn
 code