diff --git a/Gemfile b/Gemfile
index c3b181b..4540eec 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'jekyll', '4.0'
+gem 'jekyll', '4.3.3'
 gem 'rake'
 gem 'nanoc'
 gem 'stringex'
diff --git a/Gemfile.lock b/Gemfile.lock
index 11e9fab..1a9bf89 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,13 +1,13 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.8.6)
-      public_suffix (>= 2.0.2, < 6.0)
+    addressable (2.8.7)
+      public_suffix (>= 2.0.2, < 7.0)
     base64 (0.2.0)
     coderay (1.1.3)
     colorator (1.1.0)
     colored (1.2)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.3.4)
     cri (2.15.11)
     ddmetrics (1.0.1)
     ddplugin (1.0.3)
@@ -16,29 +16,30 @@ GEM
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
     eventmachine (1.2.7)
-    ffi (1.15.5)
+    ffi (1.17.0-x86_64-linux-gnu)
     forwardable-extended (2.6.0)
     http_parser.rb (0.8.0)
-    i18n (1.14.1)
+    i18n (1.14.5)
       concurrent-ruby (~> 1.0)
     immutable-ruby (0.1.0)
       concurrent-ruby (~> 1.1)
       sorted_set (~> 1.0)
-    jekyll (4.0.0)
+    jekyll (4.3.3)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
-      i18n (>= 0.9.5, < 2)
-      jekyll-sass-converter (~> 2.0)
+      i18n (~> 1.0)
+      jekyll-sass-converter (>= 2.0, < 4.0)
       jekyll-watch (~> 2.0)
-      kramdown (~> 2.1)
+      kramdown (~> 2.3, >= 2.3.1)
       kramdown-parser-gfm (~> 1.0)
       liquid (~> 4.0)
-      mercenary (~> 0.3.3)
+      mercenary (>= 0.3.6, < 0.5)
       pathutil (~> 0.9)
-      rouge (~> 3.0)
+      rouge (>= 3.0, < 5.0)
       safe_yaml (~> 1.0)
-      terminal-table (~> 1.8)
+      terminal-table (>= 1.8, < 4.0)
+      webrick (~> 1.7)
     jekyll-minibundle (3.0.0)
     jekyll-sass-converter (2.2.0)
       sassc (> 2.0.1, < 3.0)
@@ -50,11 +51,11 @@ GEM
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.4)
-    listen (3.8.0)
+    listen (3.9.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     memo_wise (1.7.0)
-    mercenary (0.3.6)
+    mercenary (0.4.0)
     method_source (1.0.0)
     nanoc (4.12.21)
       addressable (~> 2.5)
@@ -101,10 +102,10 @@ GEM
       method_source (~> 1.0)
     psych (4.0.6)
       stringio
-    public_suffix (5.0.5)
+    public_suffix (5.1.1)
     rake (13.2.1)
     rb-fsevent (0.11.2)
-    rb-inotify (0.10.1)
+    rb-inotify (0.11.1)
       ffi (~> 1.0)
     rbtree (0.4.6)
     rexml (3.3.6)
@@ -136,7 +137,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  jekyll (= 4.0)
+  jekyll (= 4.3.3)
   jekyll-minibundle
   kramdown-parser-gfm
   nanoc