diff --git a/Gemfile b/Gemfile
index 3934304..1bb18a8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,8 @@
 # the following line to use "https"
 source 'http://rubygems.org'
 
+gem "rouge", "1.7.2"
+
 gem "middleman", "~>3.3.0"
 
 # For syntax highlighting
@@ -13,7 +15,7 @@ gem 'middleman-gh-pages'
 # Live-reloading plugin
 gem "middleman-livereload", "~> 3.3.0"
 
-gem 'redcarpet', '~> 3.1.1'
+gem 'redcarpet', '~> 3.2.1'
 
 # For faster file watcher updates on Windows:
 gem "wdm", "~> 0.1.0", :platforms => [:mswin, :mingw]
@@ -23,6 +25,6 @@ platforms :mri_18 do
   gem "ruby18_source_location"
 end
 
-gem "rake", "~> 10.3.0"
+gem "rake", "~> 10.4.0"
 
 gem 'therubyracer', :platforms => :ruby
\ No newline at end of file
diff --git a/Gemfile.lock b/Gemfile.lock
index 9534eba..023bfbe 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (4.1.7)
+    activesupport (4.1.9)
       i18n (~> 0.6, >= 0.6.9)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
@@ -30,10 +30,10 @@ GEM
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     erubis (2.7.0)
-    eventmachine (1.0.3)
+    eventmachine (1.0.4)
     execjs (2.2.2)
     ffi (1.9.6)
-    haml (4.0.5)
+    haml (4.0.6)
       tilt
     hike (1.2.3)
     hitimes (1.2.2)
@@ -41,25 +41,25 @@ GEM
       uber (~> 0.0.4)
     http_parser.rb (0.6.0)
     i18n (0.6.11)
-    json (1.8.1)
+    json (1.8.2)
     kramdown (1.5.0)
     libv8 (3.16.14.7)
-    listen (2.7.11)
+    listen (2.8.5)
       celluloid (>= 0.15.2)
       rb-fsevent (>= 0.9.3)
       rb-inotify (>= 0.9)
-    middleman (3.3.6)
+    middleman (3.3.7)
       coffee-script (~> 2.2)
       compass (>= 1.0.0, < 2.0.0)
       compass-import-once (= 1.0.5)
       execjs (~> 2.0)
       haml (>= 4.0.5)
       kramdown (~> 1.2)
-      middleman-core (= 3.3.6)
+      middleman-core (= 3.3.7)
       middleman-sprockets (>= 3.1.2)
       sass (>= 3.4.0, < 4.0)
       uglifier (~> 2.5)
-    middleman-core (3.3.6)
+    middleman-core (3.3.7)
       activesupport (~> 4.1.0)
       bundler (~> 1.1)
       erubis
@@ -77,15 +77,15 @@ GEM
       em-websocket (~> 0.5.1)
       middleman-core (~> 3.2)
       rack-livereload (~> 0.3.15)
-    middleman-sprockets (3.3.10)
-      middleman-core (~> 3.3)
+    middleman-sprockets (3.4.1)
+      middleman-core (>= 3.3)
       sprockets (~> 2.12.1)
       sprockets-helpers (~> 1.1.0)
-      sprockets-sass (~> 1.2.0)
+      sprockets-sass (~> 1.3.0)
     middleman-syntax (2.0.0)
       middleman-core (~> 3.2)
       rouge (~> 1.0)
-    minitest (5.4.2)
+    minitest (5.5.1)
     multi_json (1.10.1)
     padrino-helpers (0.12.4)
       i18n (~> 0.6, >= 0.6.7)
@@ -93,20 +93,20 @@ GEM
       tilt (~> 1.4.1)
     padrino-support (0.12.4)
       activesupport (>= 3.1)
-    rack (1.5.2)
+    rack (1.6.0)
     rack-livereload (0.3.15)
       rack
-    rack-test (0.6.2)
+    rack-test (0.6.3)
       rack (>= 1.0)
-    rake (10.3.2)
+    rake (10.4.2)
     rb-fsevent (0.9.4)
     rb-inotify (0.9.5)
       ffi (>= 0.5.0)
-    redcarpet (3.1.2)
+    redcarpet (3.2.2)
     ref (1.0.5)
     rouge (1.7.2)
     ruby18_source_location (0.2)
-    sass (3.4.7)
+    sass (3.4.9)
     sprockets (2.12.3)
       hike (~> 1.2)
       multi_json (~> 1.0)
@@ -114,7 +114,7 @@ GEM
       tilt (~> 1.1, != 1.3.0)
     sprockets-helpers (1.1.0)
       sprockets (~> 2.0)
-    sprockets-sass (1.2.0)
+    sprockets-sass (1.3.1)
       sprockets (~> 2.0)
       tilt (~> 1.1)
     therubyracer (0.12.1)
@@ -127,8 +127,8 @@ GEM
       hitimes
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
-    uber (0.0.10)
-    uglifier (2.5.3)
+    uber (0.0.13)
+    uglifier (2.7.0)
       execjs (>= 0.3.0)
       json (>= 1.8.0)
 
@@ -140,8 +140,9 @@ DEPENDENCIES
   middleman-gh-pages
   middleman-livereload (~> 3.3.0)
   middleman-syntax
-  rake (~> 10.3.0)
-  redcarpet (~> 3.1.1)
+  rake (~> 10.4.0)
+  redcarpet (~> 3.2.1)
+  rouge (= 1.7.2)
   ruby18_source_location
   therubyracer
   wdm (~> 0.1.0)
diff --git a/source/javascripts/app/lang.js b/source/javascripts/app/lang.js
index 835279e..c59a16b 100644
--- a/source/javascripts/app/lang.js
+++ b/source/javascripts/app/lang.js
@@ -26,14 +26,16 @@ under the License.
     $(".lang-selector a").removeClass('active');
     $(".lang-selector a[data-language-name='" + language + "']").addClass('active');
     for (var i=0; i < languages.length; i++) {
-      $(".highlight." + languages[i]).parent().hide();
+      $(".highlight." + languages[i]).hide();
     }
-    $(".highlight." + language).parent().show();
+    $(".highlight." + language).show();
 
     global.toc.calculateHeights();
 
     // scroll to the new location of the position
-    $(window.location.hash).get(0).scrollIntoView(true);
+    if ($(window.location.hash).get(0)) {
+      $(window.location.hash).get(0).scrollIntoView(true);
+    }
   }
 
   // if a button is clicked, add the state to the history