diff --git a/Gemfile b/Gemfile
index b87e111b9a6..432d293afeb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 # Middleman
-gem 'middleman', '~>4.0.0'
+gem 'middleman', '~>4.3.11'
 gem 'middleman-gh-pages', '~> 0.0.3'
 gem 'middleman-syntax', '~> 2.1.0'
 gem 'middleman-autoprefixer', '~> 2.7.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index ff0764b8354..a5928a6473e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,79 +1,78 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.5.1)
-      i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
+    activesupport (5.2.7)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.4.0)
+    addressable (2.8.0)
+      public_suffix (>= 2.0.2, < 5.0)
     autoprefixer-rails (6.3.1)
       execjs
       json
-    backports (3.6.7)
-    capybara (2.5.0)
-      mime-types (>= 1.16)
-      nokogiri (>= 1.3.3)
-      rack (>= 1.0.0)
-      rack-test (>= 0.5.4)
-      xpath (~> 2.0)
+    backports (3.23.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
-    coffee-script-source (1.10.0)
-    compass-import-once (1.0.5)
-      sass (>= 3.2, < 3.5)
-    concurrent-ruby (0.9.2)
-    contracts (0.12.0)
+    coffee-script-source (1.12.2)
+    concurrent-ruby (1.1.10)
+    contracts (0.13.0)
+    dotenv (2.7.6)
     erubis (2.7.0)
-    execjs (2.6.0)
-    fastimage (1.8.1)
-      addressable (~> 2.3, >= 2.3.5)
-    ffi (1.9.10)
-    haml (4.0.7)
+    execjs (2.8.1)
+    fast_blank (1.0.1)
+    fastimage (2.2.6)
+    ffi (1.15.5)
+    haml (5.2.2)
+      temple (>= 0.8.0)
       tilt
-    hamster (2.0.0)
-      concurrent-ruby (~> 0.8)
-    hashie (3.4.3)
-    i18n (0.7.0)
-    json (1.8.3)
-    kramdown (1.9.0)
-    listen (3.0.5)
-      rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9)
-    middleman (4.0.0)
+    hamster (3.0.0)
+      concurrent-ruby (~> 1.0)
+    hashie (3.6.0)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
+    json (2.6.1)
+    kramdown (2.3.2)
+      rexml
+    listen (3.0.8)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
+    memoist (0.16.2)
+    middleman (4.3.11)
       coffee-script (~> 2.2)
-      compass-import-once (= 1.0.5)
       haml (>= 4.0.5)
-      kramdown (~> 1.2)
-      middleman-cli (= 4.0.0)
-      middleman-core (= 4.0.0)
-      sass (>= 3.4.0, < 4.0)
+      kramdown (>= 2.3.0)
+      middleman-cli (= 4.3.11)
+      middleman-core (= 4.3.11)
     middleman-autoprefixer (2.7.0)
       autoprefixer-rails (>= 6.3.1, < 7.0.0)
       middleman-core (>= 3.3.3)
-    middleman-cli (4.0.0)
+    middleman-cli (4.3.11)
       thor (>= 0.17.0, < 2.0)
-    middleman-core (4.0.0)
-      activesupport (~> 4.2)
-      addressable (~> 2.4.0)
+    middleman-core (4.3.11)
+      activesupport (>= 4.2, < 6.0)
+      addressable (~> 2.3)
       backports (~> 3.6)
-      bundler (~> 1.1)
-      capybara (~> 2.5.0)
-      contracts (~> 0.12.0)
+      bundler
+      contracts (~> 0.13.0)
+      dotenv
       erubis
       execjs (~> 2.0)
-      fastimage (~> 1.8)
-      hamster (~> 2.0)
+      fast_blank
+      fastimage (~> 2.0)
+      hamster (~> 3.0)
       hashie (~> 3.4)
-      i18n (~> 0.7.0)
-      listen (~> 3.0)
+      i18n (~> 0.9.0)
+      listen (~> 3.0.0)
+      memoist (~> 0.14)
       padrino-helpers (~> 0.13.0)
-      rack (>= 1.4.5, < 2.0)
-      sass (>= 3.4)
-      tilt (~> 1.4.1)
-      uglifier (~> 2.6)
+      parallel
+      rack (>= 1.4.5, < 3)
+      sassc (~> 2.0)
+      servolux
+      tilt (~> 2.0.9)
+      uglifier (~> 3.0)
     middleman-gh-pages (0.0.3)
       rake (> 0.9.3)
     middleman-sprockets (4.0.0.rc.1)
@@ -82,47 +81,42 @@ GEM
     middleman-syntax (2.1.0)
       middleman-core (>= 3.2)
       rouge (~> 1.0)
-    mime-types (3.0)
-      mime-types-data (~> 3.2015)
-    mime-types-data (3.2015.1120)
-    mini_portile2 (2.0.0)
-    minitest (5.8.4)
-    nokogiri (1.6.7.2)
-      mini_portile2 (~> 2.0.0.rc2)
-    padrino-helpers (0.13.1)
+    minitest (5.15.0)
+    padrino-helpers (0.13.3.4)
       i18n (~> 0.6, >= 0.6.7)
-      padrino-support (= 0.13.1)
-      tilt (~> 1.4.1)
-    padrino-support (0.13.1)
+      padrino-support (= 0.13.3.4)
+      tilt (>= 1.4.1, < 3)
+    padrino-support (0.13.3.4)
       activesupport (>= 3.1)
-    rack (1.6.4)
-    rack-test (0.6.3)
-      rack (>= 1.0)
+    parallel (1.22.1)
+    public_suffix (4.0.7)
+    rack (2.2.3)
     rake (10.4.2)
-    rb-fsevent (0.9.7)
-    rb-inotify (0.9.5)
-      ffi (>= 0.5.0)
+    rb-fsevent (0.11.1)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
     redcarpet (3.3.4)
+    rexml (3.2.5)
     rouge (1.10.1)
-    sass (3.4.21)
+    sassc (2.4.0)
+      ffi (~> 1.9)
+    servolux (0.13.0)
     sprockets (3.4.1)
       rack (> 1, < 3)
-    thor (0.19.1)
-    thread_safe (0.3.5)
-    tilt (1.4.1)
-    tzinfo (1.2.2)
+    temple (0.8.2)
+    thor (1.2.1)
+    thread_safe (0.3.6)
+    tilt (2.0.10)
+    tzinfo (1.2.9)
       thread_safe (~> 0.1)
-    uglifier (2.7.2)
-      execjs (>= 0.3.0)
-      json (>= 1.8.0)
-    xpath (2.0.0)
-      nokogiri (~> 1.3)
+    uglifier (3.2.0)
+      execjs (>= 0.3.0, < 3)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  middleman (~> 4.0.0)
+  middleman (~> 4.3.11)
   middleman-autoprefixer (~> 2.7.0)
   middleman-gh-pages (~> 0.0.3)
   middleman-sprockets (~> 4.0.0.rc)