diff --git a/lib/maildown/ext/action_view.rb b/lib/maildown/ext/action_view.rb
index 9d680ee..375e2ab 100644
--- a/lib/maildown/ext/action_view.rb
+++ b/lib/maildown/ext/action_view.rb
@@ -1,5 +1,20 @@
 # frozen_string_literal: true
 
+if !defined?(ActionView::OptimizedFileSystemResolver)
+  module ActionView
+    # https://github.com/codetriage/maildown/issues/59
+    #
+    # extract_handler_and_format_and_variant was removed in https://github.com/rails/rails/commit/2be8d3ebf85e26e936a7717b968737ee333d95bd
+    # OptimizedFileSystemResolver was removed in https://github.com/rails/rails/commit/faac734387124c6d780dbfcfdab721b2f26ce865
+    class OptimizedFileSystemResolver < FileSystemResolver
+      def extract_handler_and_format_and_variant(template)
+        details = @path_parser.parse(template)
+        [details.handler, details.format, details.variant]
+      end
+    end
+  end
+end
+
 # This monkeypatch allows the use of `.md.erb` file extensions
 # in addition to `.md+erb` and `.md`
 module ActionView