diff --git a/lib/github/markup/markdown.rb b/lib/github/markup/markdown.rb
index aa012d48..11cf662d 100644
--- a/lib/github/markup/markdown.rb
+++ b/lib/github/markup/markdown.rb
@@ -31,7 +31,7 @@ class Markdown < Implementation
       def initialize
         super(
           /md|mkdn?|mdwn|mdown|markdown|litcoffee/i,
-          ["Markdown", "RMarkdown", "Literate CoffeeScript"])
+          ["Markdown", "Literate CoffeeScript"])
       end
 
       def load