diff --git a/Gemfile.lock b/Gemfile.lock
index ab8330f..c2da43b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -13,8 +13,8 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.0)
     coffee-script (2.4.1)
       coffee-script-source
@@ -276,6 +276,7 @@ PLATFORMS
 DEPENDENCIES
   github-pages
   html-proofer (~> 3.0)
+  jekyll-feed
   jekyll-theme-cayman!
   rubocop (~> 0.50)
   w3c_validators (~> 1.3)