diff --git a/Gemfile b/Gemfile
index 59984a1..195bb83 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
 source "http://rubygems.org"
 
 gem 'premailer', '~> 1.10.3'
-gem 'nokogiri', '~> 1.7.1'
+gem 'nokogiri', '~> 1.13.9'
diff --git a/Gemfile.lock b/Gemfile.lock
index 5bdbcf6..7e35417 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -6,20 +6,22 @@ GEM
     css_parser (1.5.0)
       addressable
     htmlentities (4.3.4)
-    mini_portile2 (2.1.0)
-    nokogiri (1.7.1)
-      mini_portile2 (~> 2.1.0)
+    mini_portile2 (2.8.0)
+    nokogiri (1.13.9)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     premailer (1.10.3)
       addressable
       css_parser (>= 1.4.10)
       htmlentities (>= 4.0.0)
     public_suffix (2.0.5)
+    racc (1.6.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  nokogiri (~> 1.7.1)
+  nokogiri (~> 1.13.9)
   premailer (~> 1.10.3)
 
 BUNDLED WITH