diff --git a/example-site/Gemfile b/example-site/Gemfile
index 351fa64..a34d2c1 100644
--- a/example-site/Gemfile
+++ b/example-site/Gemfile
@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-gem "jekyll", "~> 3.8.6"
+gem "jekyll", "~> 4.0"
 
 gem "minima", "~> 2.0"
 
diff --git a/example-site/Gemfile.lock b/example-site/Gemfile.lock
index fb96814..490a4c3 100644
--- a/example-site/Gemfile.lock
+++ b/example-site/Gemfile.lock
@@ -1,8 +1,8 @@
 PATH
   remote: ..
   specs:
-    jekyll-external-links (0.1.3)
-      jekyll (~> 3.8)
+    jekyll-external-links (1.0.1)
+      jekyll (~> 4.0)
       nokogiri
 
 GEM
@@ -12,43 +12,47 @@ GEM
       public_suffix (>= 2.0.2, < 5.0)
     asciidoctor (2.0.10)
     colorator (1.1.0)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.6)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
-    ffi (1.11.3)
+    ffi (1.12.2)
     forwardable-extended (2.6.0)
     http_parser.rb (0.6.0)
-    i18n (0.9.5)
+    i18n (1.8.2)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.6)
+    jekyll (4.0.0)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
-      i18n (~> 0.7)
-      jekyll-sass-converter (~> 1.0)
+      i18n (>= 0.9.5, < 2)
+      jekyll-sass-converter (~> 2.0)
       jekyll-watch (~> 2.0)
-      kramdown (~> 1.14)
+      kramdown (~> 2.1)
+      kramdown-parser-gfm (~> 1.0)
       liquid (~> 4.0)
       mercenary (~> 0.3.3)
       pathutil (~> 0.9)
-      rouge (>= 1.7, < 4)
+      rouge (~> 3.0)
       safe_yaml (~> 1.0)
+      terminal-table (~> 1.8)
     jekyll-asciidoc (3.0.0)
       asciidoctor (>= 1.5.0)
       jekyll (>= 3.0.0)
     jekyll-feed (0.13.0)
       jekyll (>= 3.7, < 5.0)
-    jekyll-sass-converter (1.5.2)
-      sass (~> 3.4)
+    jekyll-sass-converter (2.1.0)
+      sassc (> 2.0.1, < 3.0)
     jekyll-seo-tag (2.6.1)
       jekyll (>= 3.3, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (1.17.0)
+    kramdown (2.1.0)
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.2.0)
+    listen (3.2.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
@@ -57,33 +61,33 @@ GEM
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
-    nokogiri (1.10.8)
+    nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (4.0.1)
+    public_suffix (4.0.4)
     rb-fsevent (0.10.3)
-    rb-inotify (0.10.0)
+    rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rouge (3.13.0)
+    rouge (3.18.0)
     safe_yaml (1.0.5)
-    sass (3.7.4)
-      sass-listen (~> 4.0.0)
-    sass-listen (4.0.0)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
+    sassc (2.2.1)
+      ffi (~> 1.9)
+    terminal-table (1.8.0)
+      unicode-display_width (~> 1.1, >= 1.1.1)
     thread_safe (0.3.6)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
     tzinfo-data (1.2019.3)
       tzinfo (>= 1.0.0)
+    unicode-display_width (1.7.0)
     wdm (0.1.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  jekyll (~> 3.8.6)
+  jekyll (~> 4.0)
   jekyll-asciidoc
   jekyll-external-links!
   minima (~> 2.0)