diff --git a/lib/oga/xml/element.rb b/lib/oga/xml/element.rb
index 79da3d7..106fa08 100644
--- a/lib/oga/xml/element.rb
+++ b/lib/oga/xml/element.rb
@@ -352,7 +352,7 @@ module Oga
         root         = root_node
 
         if root.is_a?(Document) and root.html? \
-        and !HTML_VOID_ELEMENTS.include?(name)
+        and !HTML_VOID_ELEMENTS.allow?(name)
           self_closing = false
         end
 
diff --git a/lib/oga/xml/html_void_elements.rb b/lib/oga/xml/html_void_elements.rb
index c0ee4d1..348f64e 100644
--- a/lib/oga/xml/html_void_elements.rb
+++ b/lib/oga/xml/html_void_elements.rb
@@ -4,25 +4,11 @@ module Oga
     # Names of the HTML void elements that should be handled when HTML lexing
     # is enabled.
     #
-    # @return [Oga::NodeNameSet]
+    # @return [Oga::Whitelist]
     #
-    HTML_VOID_ELEMENTS = NodeNameSet.new([
-      'area',
-      'base',
-      'br',
-      'col',
-      'command',
-      'embed',
-      'hr',
-      'img',
-      'input',
-      'keygen',
-      'link',
-      'meta',
-      'param',
-      'source',
-      'track',
-      'wbr'
-    ])
+    HTML_VOID_ELEMENTS = Whitelist.new(%w{
+      area base br col command embed hr img input keygen link meta param source
+      track wbr
+    })
   end # XML
 end # Oga
diff --git a/lib/oga/xml/lexer.rb b/lib/oga/xml/lexer.rb
index 4c38c50..756331b 100644
--- a/lib/oga/xml/lexer.rb
+++ b/lib/oga/xml/lexer.rb
@@ -466,8 +466,8 @@ module Oga
 
         # Only downcase the name if we can't find an all lower/upper version of
         # the element name. This can save us a *lot* of String allocations.
-        if HTML_VOID_ELEMENTS.include?(current_element) \
-        or HTML_VOID_ELEMENTS.include?(current_element.downcase)
+        if HTML_VOID_ELEMENTS.allow?(current_element) \
+        or HTML_VOID_ELEMENTS.allow?(current_element.downcase)
           add_token(:T_ELEM_END)
           @elements.pop
         end