diff --git a/lib/jekyll/tags/highlight.rb b/lib/jekyll/tags/highlight.rb
index 29a6ea0a..f88cfc9d 100644
--- a/lib/jekyll/tags/highlight.rb
+++ b/lib/jekyll/tags/highlight.rb
@@ -83,7 +83,7 @@ eos
 
       def add_code_tag(code)
         # Add nested <code> tags to code blocks
-        code = code.sub(/<pre>\n*/,'<pre><code class="' + @lang.to_s.gsub("+", "-") + '">')
+        code = code.sub(/<pre>\n*/,'<pre><code class="language-' + @lang.to_s.gsub("+", "-") + '" data-lang="' + @lang.to_s + '">')
         code = code.sub(/\n*<\/pre>/,"</code></pre>")
         code.strip
       end
diff --git a/test/test_tags.rb b/test/test_tags.rb
index 7f2dd4d5..f34030e0 100644
--- a/test/test_tags.rb
+++ b/test/test_tags.rb
@@ -91,11 +91,11 @@ CONTENT
     end
 
     should "render markdown with pygments" do
-      assert_match %{<pre><code class="text">test</code></pre>}, @result
+      assert_match %{<pre><code class="language-text" data-lang="text">test</code></pre>}, @result
     end
 
     should "render markdown with pygments with line numbers" do
-      assert_match %{<pre><code class="text"><span class="lineno">1</span> test</code></pre>}, @result
+      assert_match %{<pre><code class="language-text" data-lang="text"><span class="lineno">1</span> test</code></pre>}, @result
     end
   end
 
@@ -105,7 +105,7 @@ CONTENT
     end
 
     should "not embed the file" do
-      assert_match %{<pre><code class="text">./jekyll.gemspec</code></pre>}, @result
+      assert_match %{<pre><code class="language-text" data-lang="text">./jekyll.gemspec</code></pre>}, @result
     end
   end
 
@@ -115,7 +115,7 @@ CONTENT
     end
 
     should "render markdown with pygments line handling" do
-      assert_match %{<pre><code class="text">Æ</code></pre>}, @result
+      assert_match %{<pre><code class="language-text" data-lang="text">Æ</code></pre>}, @result
     end
   end