diff --git a/Gemfile b/Gemfile
index 5c56f99..8111017 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'http://rubygems.org'
 
-gem "middleman", "~>3.1.6"
+gem "middleman", "~>4.3.2"
 gem 'middleman-deploy'
 
 # For faster file watcher updates on Windows:
diff --git a/Gemfile.lock b/Gemfile.lock
index c5e220e..38457ae 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,98 +1,111 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (3.2.15)
-      i18n (~> 0.6, >= 0.6.4)
-      multi_json (~> 1.0)
-    chunky_png (1.2.9)
-    coffee-script (2.2.0)
+    activesupport (5.0.7.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    addressable (2.5.2)
+      public_suffix (>= 2.0.2, < 4.0)
+    backports (3.11.4)
+    coffee-script (2.4.1)
       coffee-script-source
       execjs
-    coffee-script-source (1.6.3)
-    compass (0.12.2)
-      chunky_png (~> 1.2)
-      fssm (>= 0.2.7)
-      sass (~> 3.1)
-    execjs (1.4.0)
-      multi_json (~> 1.0)
-    ffi (1.9.1)
-    fssm (0.2.10)
-    haml (4.0.3)
+    coffee-script-source (1.12.2)
+    concurrent-ruby (1.1.4)
+    contracts (0.13.0)
+    dotenv (2.6.0)
+    erubis (2.7.0)
+    execjs (2.7.0)
+    fast_blank (1.0.0)
+    fastimage (2.1.5)
+    ffi (1.9.25)
+    haml (5.0.4)
+      temple (>= 0.8.0)
       tilt
-    hike (1.2.3)
-    i18n (0.6.5)
-    kramdown (1.2.0)
-    listen (1.3.1)
-      rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9)
-      rb-kqueue (>= 0.2)
-    middleman (3.1.6)
-      coffee-script (~> 2.2.0)
-      compass (>= 0.12.2)
-      execjs (~> 1.4.0)
-      haml (>= 3.1.6)
+    hamster (3.0.0)
+      concurrent-ruby (~> 1.0)
+    hashie (3.6.0)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
+    kramdown (1.17.0)
+    listen (3.0.8)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
+    memoist (0.16.0)
+    middleman (4.3.2)
+      coffee-script (~> 2.2)
+      haml (>= 4.0.5)
       kramdown (~> 1.2)
-      middleman-core (= 3.1.6)
-      middleman-more (= 3.1.6)
-      middleman-sprockets (>= 3.1.2)
-      sass (>= 3.1.20)
-      uglifier (~> 2.1.0)
-    middleman-core (3.1.6)
-      activesupport (~> 3.2.6)
-      bundler (~> 1.1)
-      i18n (~> 0.6.1)
-      listen (~> 1.1)
-      rack (>= 1.4.5)
-      rack-test (~> 0.6.1)
-      thor (>= 0.15.2, < 2.0)
-      tilt (~> 1.3.6)
+      middleman-cli (= 4.3.2)
+      middleman-core (= 4.3.2)
+    middleman-cli (4.3.2)
+      thor (>= 0.17.0, < 2.0)
+    middleman-core (4.3.2)
+      activesupport (>= 4.2, < 5.1)
+      addressable (~> 2.3)
+      backports (~> 3.6)
+      bundler
+      contracts (~> 0.13.0)
+      dotenv
+      erubis
+      execjs (~> 2.0)
+      fast_blank
+      fastimage (~> 2.0)
+      hamster (~> 3.0)
+      hashie (~> 3.4)
+      i18n (~> 0.9.0)
+      listen (~> 3.0.0)
+      memoist (~> 0.14)
+      padrino-helpers (~> 0.13.0)
+      parallel
+      rack (>= 1.4.5, < 3)
+      sassc (~> 2.0)
+      servolux
+      tilt (~> 2.0.9)
+      uglifier (~> 3.0)
     middleman-deploy (0.1.2)
       middleman-core (>= 3.0.0)
       net-sftp
       ptools
-    middleman-more (3.1.6)
-    middleman-sprockets (3.1.4)
-      middleman-core (>= 3.0.14)
-      middleman-more (>= 3.0.14)
-      sprockets (~> 2.1)
-      sprockets-helpers (~> 1.0.0)
-      sprockets-sass (~> 1.0.0)
-    multi_json (1.8.2)
+    minitest (5.11.3)
     net-sftp (2.1.2)
       net-ssh (>= 2.6.5)
     net-ssh (2.6.8)
+    padrino-helpers (0.13.3.4)
+      i18n (~> 0.6, >= 0.6.7)
+      padrino-support (= 0.13.3.4)
+      tilt (>= 1.4.1, < 3)
+    padrino-support (0.13.3.4)
+      activesupport (>= 3.1)
+    parallel (1.12.1)
     ptools (1.2.2)
-    rack (1.5.2)
-    rack-test (0.6.2)
-      rack (>= 1.0)
-    rb-fsevent (0.9.3)
-    rb-inotify (0.9.2)
-      ffi (>= 0.5.0)
-    rb-kqueue (0.2.0)
-      ffi (>= 0.5.0)
+    public_suffix (3.0.3)
+    rack (2.0.6)
+    rake (12.3.2)
+    rb-fsevent (0.10.3)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
     ruby18_source_location (0.2)
-    sass (3.2.12)
-    sprockets (2.10.0)
-      hike (~> 1.2)
-      multi_json (~> 1.0)
-      rack (~> 1.0)
-      tilt (~> 1.1, != 1.3.0)
-    sprockets-helpers (1.0.1)
-      sprockets (~> 2.0)
-    sprockets-sass (1.0.2)
-      sprockets (~> 2.0)
-      tilt (~> 1.1)
-    thor (0.18.1)
-    tilt (1.3.7)
-    uglifier (2.1.2)
-      execjs (>= 0.3.0)
-      multi_json (~> 1.0, >= 1.0.2)
+    sassc (2.0.0)
+      ffi (~> 1.9.6)
+      rake
+    servolux (0.13.0)
+    temple (0.8.0)
+    thor (0.20.3)
+    thread_safe (0.3.6)
+    tilt (2.0.9)
+    tzinfo (1.2.5)
+      thread_safe (~> 0.1)
+    uglifier (3.2.0)
+      execjs (>= 0.3.0, < 3)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  middleman (~> 3.1.6)
+  middleman (~> 4.3.2)
   middleman-deploy
   ruby18_source_location
   wdm (~> 0.1.0)