diff --git a/Gemfile b/Gemfile
index 89cdc57..8de7fbb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,5 +7,5 @@ group :development, :test do
   gem 'fasterer', '~> 0.8', require: false
   gem 'rake', '~> 13.0'
   gem 'rspec', '~> 3.9'
-  gem 'rubocop', '~> 0.90', require: false
+  gem 'rubocop', '~> 0.91', require: false
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 190b419..b552e21 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -18,7 +18,7 @@ GEM
       ast (~> 2.4.1)
     rainbow (3.0.0)
     rake (13.0.1)
-    regexp_parser (1.7.1)
+    regexp_parser (1.8.0)
     rexml (3.2.4)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
@@ -33,13 +33,13 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
     rspec-support (3.9.3)
-    rubocop (0.90.0)
+    rubocop (0.91.1)
       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 (0.4.2)
@@ -63,7 +63,7 @@ DEPENDENCIES
   fasterer (~> 0.8)
   rake (~> 13.0)
   rspec (~> 3.9)
-  rubocop (~> 0.90)
+  rubocop (~> 0.91)
 
 RUBY VERSION
    ruby 2.7.0p0