diff --git a/Gemfile b/Gemfile
index 66cbb27..e3a6659 100644
--- a/Gemfile
+++ b/Gemfile
@@ -42,7 +42,7 @@ group :development, :test do
   # Omakase Ruby styling [https://github.com/rails/rubocop-rails-omakase/]
   gem "rspec-rails"
   gem "capybara"
-  gem 'shoulda-matchers', '~> 5.0'
+  gem 'shoulda-matchers', '~> 6.4'
   gem "faker"
   gem "rails-controller-testing"
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 40be8f1..f9e9229 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -142,7 +142,7 @@ GEM
     marcel (1.0.4)
     matrix (0.4.2)
     mini_mime (1.1.5)
-    minitest (5.24.1)
+    minitest (5.25.1)
     msgpack (1.7.2)
     net-imap (0.4.14)
       date
@@ -272,7 +272,7 @@ GEM
       sprockets-rails
       tilt
     securerandom (0.3.1)
-    shoulda-matchers (5.3.0)
+    shoulda-matchers (6.4.0)
       activesupport (>= 5.2.0)
     sprockets (4.2.1)
       concurrent-ruby (~> 1.0)
@@ -329,7 +329,7 @@ DEPENDENCIES
   rspec-rails
   rubocop-rails-omakase
   sassc-rails
-  shoulda-matchers (~> 5.0)
+  shoulda-matchers (~> 6.4)
   sprockets-rails
   sqlite3 (>= 1.4)
   stimulus-rails