diff --git a/R/add_header_above.R b/R/add_header_above.R
index 1242868..5384f4d 100644
--- a/R/add_header_above.R
+++ b/R/add_header_above.R
@@ -53,8 +53,7 @@
 
   new_header_row <- htmlTable_new_header_generator(header, bold, italic)
   xml_add_child(kable_xml_thead, new_header_row, .where = 0)
-  out <- structure(as.character(kable_xml), format = "html",
-                   class = "knitr_kable")
+  out <- as_kable_xml(kable_xml)
   attributes(out) <- kable_attrs
   return(out)
 }