diff --git a/Gemfile b/Gemfile
index c2270216..564a33cf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,9 +2,13 @@ source 'https://rubygems.org'
 
 gem 'faraday', '~> 1.0.0'
 gem 'govuk-lint', '~> 4.0.1'
-gem 'govuk_tech_docs', '~> 2.2.2'
+gem 'govuk_tech_docs', '~> 2.4.2'
 gem 'mini_racer', '~> 0.3.1'
 
+# Include specific version of FFI until following issue is fixed:
+# https://github.com/ffi/ffi/issues/791
+gem "ffi", "1.12"
+
 group :test do
   gem 'rspec', '~> 3.9.0'
   gem 'webmock', '~> 3.8.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index fb670346..0fa675bc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (5.2.4.5)
+    activesupport (5.2.6)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -9,17 +9,16 @@ GEM
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     ast (2.4.0)
-    autoprefixer-rails (9.8.6.5)
-      execjs
-    backports (3.20.2)
+    autoprefixer-rails (10.2.5.1)
+      execjs (> 0)
+    backports (3.21.0)
     chronic (0.10.2)
     chunky_png (1.4.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    commonmarker (0.21.2)
-      ruby-enum (~> 0.5)
+    commonmarker (0.22.0)
     compass (1.0.3)
       chunky_png (~> 1.2)
       compass-core (~> 1.0.2)
@@ -32,7 +31,7 @@ GEM
       sass (>= 3.3.0, < 3.5)
     compass-import-once (1.0.5)
       sass (>= 3.2, < 3.5)
-    concurrent-ruby (1.1.8)
+    concurrent-ruby (1.1.9)
     contracts (0.13.0)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
@@ -43,18 +42,19 @@ GEM
       http_parser.rb (~> 0.6.0)
     erubis (2.7.0)
     eventmachine (1.2.7)
-    execjs (2.7.0)
+    execjs (2.8.1)
     faraday (1.0.0)
       multipart-post (>= 1.2, < 3)
     fast_blank (1.0.0)
-    fastimage (2.2.3)
-    ffi (1.15.0)
+    fastimage (2.2.4)
+    ffi (1.12.0)
     govuk-lint (4.0.1)
       rubocop (~> 0.72)
       rubocop-rails (~> 2)
       rubocop-rspec (~> 1.28)
       scss_lint
-    govuk_tech_docs (2.2.2)
+    govuk_tech_docs (2.4.2)
+      autoprefixer-rails (~> 10.2)
       chronic (~> 0.10.2)
       middleman (~> 4.0)
       middleman-autoprefixer (~> 2.10.0)
@@ -65,8 +65,8 @@ GEM
       middleman-syntax (~> 3.2.0)
       nokogiri
       openapi3_parser (~> 0.9.0)
-      redcarpet (~> 3.5.0)
-    haml (5.2.1)
+      redcarpet (~> 3.5.1)
+    haml (5.2.2)
       temple (>= 0.8.0)
       tilt
     hamster (3.0.0)
@@ -90,8 +90,8 @@ GEM
       kramdown (>= 2.3.0)
       middleman-cli (= 4.3.11)
       middleman-core (= 4.3.11)
-    middleman-autoprefixer (2.10.1)
-      autoprefixer-rails (~> 9.1)
+    middleman-autoprefixer (2.10.0)
+      autoprefixer-rails (>= 9.1.4)
       middleman-core (>= 3.3.3)
     middleman-cli (4.3.11)
       thor (>= 0.17.0, < 2.0)
@@ -121,7 +121,7 @@ GEM
       servolux
       tilt (~> 2.0.9)
       uglifier (~> 3.0)
-    middleman-livereload (3.4.6)
+    middleman-livereload (3.4.7)
       em-websocket (~> 0.5.1)
       middleman-core (>= 3.3)
       rack-livereload (~> 0.3.15)
@@ -135,13 +135,13 @@ GEM
     middleman-syntax (3.2.0)
       middleman-core (>= 3.2)
       rouge (~> 3.2)
-    mini_portile2 (2.5.1)
+    mini_portile2 (2.5.3)
     mini_racer (0.3.1)
       libv8 (~> 8.4.255)
     minitest (5.14.4)
     multi_json (1.15.0)
     multipart-post (2.1.1)
-    nokogiri (1.11.4)
+    nokogiri (1.11.7)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
     openapi3_parser (0.9.0)
@@ -156,7 +156,7 @@ GEM
     parallel (1.19.1)
     parser (2.6.5.0)
       ast (~> 2.4.0)
-    psych (3.3.1)
+    psych (3.3.2)
     public_suffix (4.0.6)
     racc (1.5.2)
     rack (2.2.3)
@@ -164,7 +164,7 @@ GEM
       rack
     rainbow (3.0.0)
     rake (12.3.3)
-    rb-fsevent (0.10.4)
+    rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redcarpet (3.5.1)
@@ -195,8 +195,6 @@ GEM
       rubocop (>= 0.72.0)
     rubocop-rspec (1.36.0)
       rubocop (>= 0.68.1)
-    ruby-enum (0.9.0)
-      i18n
     ruby-progressbar (1.10.1)
     safe_yaml (1.0.5)
     sass (3.4.25)
@@ -228,8 +226,9 @@ PLATFORMS
 
 DEPENDENCIES
   faraday (~> 1.0.0)
+  ffi (= 1.12)
   govuk-lint (~> 4.0.1)
-  govuk_tech_docs (~> 2.2.2)
+  govuk_tech_docs (~> 2.4.2)
   mini_racer (~> 0.3.1)
   rspec (~> 3.9.0)
   webmock (~> 3.8.2)