diff --git a/Gemfile.lock b/Gemfile.lock
index bc4d50e..170f8f1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,13 +3,13 @@ PATH
   specs:
     acme_plugin (0.0.13)
       acme-client (~> 0.6.2)
-      nokogiri (~> 1.8.1)
+      nokogiri (>= 1.8.1, < 1.14.0)
       rails (>= 4.2)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    acme-client (0.6.2)
+    acme-client (0.6.3)
       faraday (~> 0.9, >= 0.9.1)
     actioncable (5.1.2)
       actionpack (= 5.1.2)
@@ -61,20 +61,20 @@ GEM
       safe_yaml (~> 1.0.0)
     docile (1.1.5)
     erubi (1.6.1)
-    faraday (0.14.0)
+    faraday (0.17.5)
       multipart-post (>= 1.2, < 3)
-    globalid (0.4.1)
-      activesupport (>= 4.2.0)
+    globalid (1.0.0)
+      activesupport (>= 5.0)
     hashdiff (0.3.7)
     i18n (0.8.4)
     json (2.1.0)
     loofah (2.0.3)
       nokogiri (>= 1.5.9)
-    mail (2.7.0)
+    mail (2.7.1)
       mini_mime (>= 0.1.1)
     method_source (0.8.2)
-    mini_mime (1.0.0)
-    mini_portile2 (2.3.0)
+    mini_mime (1.1.2)
+    mini_portile2 (2.8.0)
     minitest (5.11.3)
     minitest-rails (3.0.0)
       minitest (~> 5.8)
@@ -84,15 +84,17 @@ GEM
       builder
       minitest (>= 5.0)
       ruby-progressbar
-    multipart-post (2.0.0)
-    nio4r (2.2.0)
-    nokogiri (1.8.2)
-      mini_portile2 (~> 2.3.0)
+    multipart-post (2.1.1)
+    nio4r (2.5.8)
+    nokogiri (1.13.4)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     parallel (1.12.1)
     parser (2.5.0.2)
       ast (~> 2.4.0)
     powerpack (0.1.1)
     public_suffix (3.0.2)
+    racc (1.6.0)
     rack (2.0.3)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -135,10 +137,10 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sprockets (3.7.1)
+    sprockets (4.0.3)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
+    sprockets-rails (3.2.2)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
@@ -154,7 +156,7 @@ GEM
       hashdiff
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.3)
+    websocket-extensions (0.1.5)
 
 PLATFORMS
   ruby
diff --git a/acme_plugin.gemspec b/acme_plugin.gemspec
index ddcba7b..24a3540 100644
--- a/acme_plugin.gemspec
+++ b/acme_plugin.gemspec
@@ -24,7 +24,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency 'acme-client', '~>0.6.2'
   s.add_dependency 'rails', '>=4.2'
-  s.add_dependency 'nokogiri', '~>1.8.1'
+  s.add_dependency 'nokogiri', '>=1.8.1', '<1.14.0'
 
   s.add_development_dependency 'codeclimate-test-reporter', '~>1.0.8'
   s.add_development_dependency 'minitest', '~>5.11.3'