diff --git a/lib/linguist/language.rb b/lib/linguist/language.rb
index 9d59aef9..1b9ed814 100644
--- a/lib/linguist/language.rb
+++ b/lib/linguist/language.rb
@@ -25,7 +25,7 @@ module Linguist
     #
     # Returns an array
     def self.detectable_markup
-      ["CSS", "Less", "Sass", "Markdown", "Textile", "reStructuredText", "AsciiDoc"]
+      ["CSS", "Less", "Sass", "Markdown", "Textile", "reStructuredText", "AsciiDoc", "RDoc"]
     end
 
     # Internal: Create a new Language object
diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index e9d9281e..7b8109b1 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -1149,6 +1149,13 @@ Rebol:
 Redcode:
   primary_extension: .cw
 
+RDoc:
+  type: markup
+  lexer: Text only
+  ace_mode: rdoc
+  wrap: true
+  primary_extension: .rdoc
+
 Rouge:
   type: programming
   lexer: Clojure