diff --git a/lib/nokogumbo.rb b/lib/nokogumbo.rb
index 262d45b9..ce1679c5 100644
--- a/lib/nokogumbo.rb
+++ b/lib/nokogumbo.rb
@@ -1,17 +1,38 @@
 require 'nokogiri'
 require 'nokogumbo/version'
-require 'nokogumbo/html5'
 
-require 'nokogumbo/nokogumbo'
+if ((defined?(Nokogiri::HTML5) && Nokogiri::HTML5.respond_to?(:parse)) &&
+    (defined?(Nokogiri::Gumbo) && Nokogiri::Gumbo.respond_to?(:parse)) &&
+    !(ENV.key?("NOKOGUMBO_IGNORE_NOKOGIRI_HTML5") && ENV["NOKOGUMBO_IGNORE_NOKOGIRI_HTML5"] != "false"))
 
-module Nokogumbo
-  # The default maximum number of attributes per element.
-  DEFAULT_MAX_ATTRIBUTES = 400
+  warn "NOTE: nokogumbo: Using Nokogiri::HTML5 provided by Nokogiri. See https://github.com/sparklemotion/nokogiri/issues/2205 for more information."
 
-  # The default maximum number of errors for parsing a document or a fragment.
-  DEFAULT_MAX_ERRORS = 0
+  module Nokogumbo
+    def self.parse(*args)
+      Nokogiri::Gumbo.parse(*args)
+    end
 
-  # The default maximum depth of the DOM tree produced by parsing a document
-  # or fragment.
-  DEFAULT_MAX_TREE_DEPTH = 400
+    def self.fragment(*args)
+      Nokogiri::Gumbo.fragment(*args)
+    end
+
+    DEFAULT_MAX_ATTRIBUTES = Nokogiri::Gumbo::DEFAULT_MAX_ATTRIBUTES
+    DEFAULT_MAX_ERRORS = Nokogiri::Gumbo::DEFAULT_MAX_ERRORS
+    DEFAULT_MAX_TREE_DEPTH = Nokogiri::Gumbo::DEFAULT_MAX_TREE_DEPTH
+  end
+else
+  require 'nokogumbo/html5'
+  require 'nokogumbo/nokogumbo'
+
+  module Nokogumbo
+    # The default maximum number of attributes per element.
+    DEFAULT_MAX_ATTRIBUTES = 400
+
+    # The default maximum number of errors for parsing a document or a fragment.
+    DEFAULT_MAX_ERRORS = 0
+
+    # The default maximum depth of the DOM tree produced by parsing a document
+    # or fragment.
+    DEFAULT_MAX_TREE_DEPTH = 400
+  end
 end