Apply class kableExtra to all HTML functions
diff --git a/R/row_spec.R b/R/row_spec.R
index deedf68..88bf499 100644
--- a/R/row_spec.R
+++ b/R/row_spec.R
@@ -97,6 +97,7 @@
 
   out <- as_kable_xml(kable_xml)
   attributes(out) <- kable_attrs
+  if (!"kableExtra" %in% class(out)) class(out) <- c("kableExtra", class(out))
   return(out)
 }