diff --git a/lib/travis/yaml/nodes/language.rb b/lib/travis/yaml/nodes/language.rb
index ce7828a..e90eb81 100644
--- a/lib/travis/yaml/nodes/language.rb
+++ b/lib/travis/yaml/nodes/language.rb
@@ -5,7 +5,7 @@ class Language < FixedValue
       default :ruby
 
       value :c, :cpp, :clojure, :d, :dart, :erlang, :go, :groovy, :haskell, :haxe, :java,
-            :node_js, :"objective-c", :ruby, :rust, :python, :perl, :php, :scala,
+            :node_js, :"objective-c", :r, :ruby, :rust, :python, :perl, :php, :scala,
             :android, :crystal, :csharp, :smalltalk
       value dartlang: :dart, jvm: :java, javascript: :node_js, node: :node_js,
             nodejs: :node_js, golang: :go, objective_c: :"objective-c",
diff --git a/spec/nodes/language_spec.rb b/spec/nodes/language_spec.rb
index 7472c2c..cec3b01 100644
--- a/spec/nodes/language_spec.rb
+++ b/spec/nodes/language_spec.rb
@@ -75,5 +75,13 @@
       expect(config.language)           .to be == 'node_js'
       expect(config.language.warnings)  .to include('does not support multiple values, dropping "ruby"')
     end
+
+    specify 'supports all un-aliased languages' do
+      languages = Travis::Yaml::Nodes::Language.valid_values
+      languages.each do |lang|
+        config = Travis::Yaml.parse("language: #{lang}")
+        expect(config.language).to be == lang
+      end
+    end
   end
-end
\ No newline at end of file
+end