diff --git a/Gemfile b/Gemfile
index 2b374568e8..e907e25fbd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -52,7 +52,7 @@ gem 'rb-readline'
 gem 'rdiscount', '~> 2.2'
 gem "recaptcha", require: "recaptcha/rails"
 gem 'responders', '~> 3.0'
-gem 'rubocop', '~> 0.90.0', require: false
+gem 'rubocop', '~> 0.91.0', require: false
 gem "ruby-openid", :require => "openid"
 gem 'sanitize'
 gem 'sentry-raven'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7282dfe2a3..3ef573721f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -459,16 +459,16 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
     rspec-support (3.9.0)
-    rubocop (0.90.0)
+    rubocop (0.91.0)
       parallel (~> 1.10)
       parser (>= 2.7.1.1)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.7)
       rexml
-      rubocop-ast (>= 0.3.0, < 1.0)
+      rubocop-ast (>= 0.4.0, < 1.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 2.0)
-    rubocop-ast (0.3.0)
+    rubocop-ast (0.4.2)
       parser (>= 2.7.1.4)
     ruby-openid (2.9.2)
     ruby-progressbar (1.10.1)
@@ -666,7 +666,7 @@ DEPENDENCIES
   rest-client
   reverse_markdown
   rspec
-  rubocop (~> 0.90.0)
+  rubocop (~> 0.91.0)
   ruby-openid
   sanitize
   sassc-rails