diff --git a/Gemfile b/Gemfile
index ae2b3561..9905f64a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,7 @@ gem 'systemu', '~> 2.6.5'
 gem 'adsf', '~> 1.2.0'
 gem 'sass', '~> 3.4.21'
 gem 'rdiscount', '~> 2.1.8'
-gem 'nokogiri', '~> 1.10.8'
+gem 'nokogiri', '~> 1.13.6'
 gem 'feedjira', '~> 2.0.0'
 gem 'ri_cal', '~> 0.8.8'
 gem 'rqrcode_png', '~> 0.1.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index f1c8e59d..44872076 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -64,14 +64,15 @@ GEM
     memoizable (0.4.2)
       thread_safe (~> 0.3, >= 0.3.1)
     method_source (0.9.0)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.8.0)
     multipart-post (2.0.0)
     nanoc (3.7.5)
       cri (~> 2.3)
     naught (1.1.0)
     nenv (0.3.0)
-    nokogiri (1.10.8)
-      mini_portile2 (~> 2.4.0)
+    nokogiri (1.13.6)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     notiffany (0.1.1)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -80,6 +81,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.1)
+    racc (1.6.0)
     rack (2.2.3)
     rb-fsevent (0.10.2)
     rb-inotify (0.9.10)
@@ -132,7 +134,7 @@ DEPENDENCIES
   feedjira (~> 2.0.0)
   guard-nanoc (~> 1.0.3)
   nanoc (~> 3.7.5)
-  nokogiri (~> 1.10.8)
+  nokogiri (~> 1.13.6)
   rdiscount (~> 2.1.8)
   ri_cal (~> 0.8.8)
   rqrcode_png (~> 0.1.5)