diff --git a/Library/Homebrew/Gemfile.lock b/Library/Homebrew/Gemfile.lock
index 299cff8cb0..435a725bd6 100644
--- a/Library/Homebrew/Gemfile.lock
+++ b/Library/Homebrew/Gemfile.lock
@@ -56,6 +56,7 @@ GEM
     plist (3.5.0)
     rainbow (3.0.0)
     rdiscount (2.2.0.1)
+    rexml (3.2.4)
     ronn (0.7.3)
       hpricot (>= 0.8.2)
       mustache (>= 0.7.0)
@@ -80,11 +81,12 @@ GEM
     rspec-support (3.9.2)
     rspec-wait (0.0.9)
       rspec (>= 3, < 4)
-    rubocop (0.79.0)
+    rubocop (0.80.0)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
       parser (>= 2.7.0.1)
       rainbow (>= 2.2.2, < 4.0)
+      rexml
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 1.7)
     rubocop-performance (1.5.2)