diff --git a/lib/kramdown/converter/syntax_highlighter/rouge.rb b/lib/kramdown/converter/syntax_highlighter/rouge.rb
index c799526c..ed6a4f83 100644
--- a/lib/kramdown/converter/syntax_highlighter/rouge.rb
+++ b/lib/kramdown/converter/syntax_highlighter/rouge.rb
@@ -70,7 +70,7 @@ def self.formatter_class(opts = {})
       when Class
         formatter
       when /\A[[:upper:]][[:alnum:]_]*\z/
-        ::Rouge::Formatters.const_get(formatter)
+        ::Rouge::Formatters.const_get(formatter, false)
       else
         # Available in Rouge 2.0 or later
         ::Rouge::Formatters::HTMLLegacy
diff --git a/test/test_files.rb b/test/test_files.rb
index b446b3bc..7e2ccad3 100644
--- a/test/test_files.rb
+++ b/test/test_files.rb
@@ -21,16 +21,20 @@
   end
 
   # custom formatter for tests
-  class RougeHTMLFormatters < Kramdown::Converter::SyntaxHighlighter::Rouge.formatter_class
+  module Rouge
+    module Formatters
+      class RougeHTMLFormatters < Kramdown::Converter::SyntaxHighlighter::Rouge.formatter_class
 
-    tag 'rouge_html_formatters'
+        tag 'rouge_html_formatters'
 
-    def stream(tokens, &b)
-      yield %(<div class="custom-class">)
-      super
-      yield %(</div>)
-    end
+        def stream(tokens, &b)
+          yield %(<div class="custom-class">)
+          super
+          yield %(</div>)
+        end
 
+      end
+    end
   end
 rescue LoadError, SyntaxError, NameError
 end