diff --git a/Gemfile b/Gemfile
index 6c1f8003b..c3e974333 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ source 'https://rubygems.org'
 ruby '3.4.7'
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
-gem 'rails', '~> 8.0.3'
+gem 'rails', '~> 8.1.2'
 # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
 gem 'sprockets-rails'
 # Use postgresql as the database for Active Record
diff --git a/Gemfile.lock b/Gemfile.lock
index 42772f704..c24aad3ac 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,29 +2,31 @@ GEM
   remote: https://rubygems.org/
   specs:
     action_args (2.7.3)
-    actioncable (8.0.3)
-      actionpack (= 8.0.3)
-      activesupport (= 8.0.3)
+    action_text-trix (2.1.16)
+      railties
+    actioncable (8.1.2)
+      actionpack (= 8.1.2)
+      activesupport (= 8.1.2)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
       zeitwerk (~> 2.6)
-    actionmailbox (8.0.3)
-      actionpack (= 8.0.3)
-      activejob (= 8.0.3)
-      activerecord (= 8.0.3)
-      activestorage (= 8.0.3)
-      activesupport (= 8.0.3)
+    actionmailbox (8.1.2)
+      actionpack (= 8.1.2)
+      activejob (= 8.1.2)
+      activerecord (= 8.1.2)
+      activestorage (= 8.1.2)
+      activesupport (= 8.1.2)
       mail (>= 2.8.0)
-    actionmailer (8.0.3)
-      actionpack (= 8.0.3)
-      actionview (= 8.0.3)
-      activejob (= 8.0.3)
-      activesupport (= 8.0.3)
+    actionmailer (8.1.2)
+      actionpack (= 8.1.2)
+      actionview (= 8.1.2)
+      activejob (= 8.1.2)
+      activesupport (= 8.1.2)
       mail (>= 2.8.0)
       rails-dom-testing (~> 2.2)
-    actionpack (8.0.3)
-      actionview (= 8.0.3)
-      activesupport (= 8.0.3)
+    actionpack (8.1.2)
+      actionview (= 8.1.2)
+      activesupport (= 8.1.2)
       nokogiri (>= 1.8.5)
       rack (>= 2.2.4)
       rack-session (>= 1.0.1)
@@ -32,44 +34,45 @@ GEM
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
       useragent (~> 0.16)
-    actiontext (8.0.3)
-      actionpack (= 8.0.3)
-      activerecord (= 8.0.3)
-      activestorage (= 8.0.3)
-      activesupport (= 8.0.3)
+    actiontext (8.1.2)
+      action_text-trix (~> 2.1.15)
+      actionpack (= 8.1.2)
+      activerecord (= 8.1.2)
+      activestorage (= 8.1.2)
+      activesupport (= 8.1.2)
       globalid (>= 0.6.0)
       nokogiri (>= 1.8.5)
-    actionview (8.0.3)
-      activesupport (= 8.0.3)
+    actionview (8.1.2)
+      activesupport (= 8.1.2)
       builder (~> 3.1)
       erubi (~> 1.11)
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
     active_decorator (1.5.1)
       activesupport
-    activejob (8.0.3)
-      activesupport (= 8.0.3)
+    activejob (8.1.2)
+      activesupport (= 8.1.2)
       globalid (>= 0.3.6)
-    activemodel (8.0.3)
-      activesupport (= 8.0.3)
-    activerecord (8.0.3)
-      activemodel (= 8.0.3)
-      activesupport (= 8.0.3)
+    activemodel (8.1.2)
+      activesupport (= 8.1.2)
+    activerecord (8.1.2)
+      activemodel (= 8.1.2)
+      activesupport (= 8.1.2)
       timeout (>= 0.4.0)
-    activestorage (8.0.3)
-      actionpack (= 8.0.3)
-      activejob (= 8.0.3)
-      activerecord (= 8.0.3)
-      activesupport (= 8.0.3)
+    activestorage (8.1.2)
+      actionpack (= 8.1.2)
+      activejob (= 8.1.2)
+      activerecord (= 8.1.2)
+      activesupport (= 8.1.2)
       marcel (~> 1.0)
-    activesupport (8.0.3)
+    activesupport (8.1.2)
       base64
-      benchmark (>= 0.3)
       bigdecimal
       concurrent-ruby (~> 1.0, >= 1.3.1)
       connection_pool (>= 2.2.5)
       drb
       i18n (>= 1.6, < 2)
+      json
       logger (>= 1.4.2)
       minitest (>= 5.1)
       securerandom (>= 0.3)
@@ -111,7 +114,6 @@ GEM
       multi_json (~> 1)
       statsd-ruby (~> 1.1)
     base64 (0.3.0)
-    benchmark (0.5.0)
     bigdecimal (4.0.1)
     bindex (0.8.1)
     bootsnap (1.20.1)
@@ -239,8 +241,9 @@ GEM
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     io-console (0.8.2)
-    irb (1.16.0)
+    irb (1.17.0)
       pp (>= 0.6.0)
+      prism (>= 1.3.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     jmespath (1.6.2)
@@ -270,7 +273,8 @@ GEM
     loofah (2.25.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
-    mail (2.8.1)
+    mail (2.9.0)
+      logger
       mini_mime (>= 0.1.1)
       net-imap
       net-pop
@@ -289,7 +293,7 @@ GEM
     multi_xml (0.8.0)
       bigdecimal (>= 3.1, < 5)
     multipart-post (2.4.1)
-    net-imap (0.5.10)
+    net-imap (0.6.3)
       date
       net-protocol
     net-pop (0.1.2)
@@ -299,7 +303,7 @@ GEM
     net-smtp (0.5.1)
       net-protocol
     netrc (0.11.0)
-    nio4r (2.7.4)
+    nio4r (2.7.5)
     nokogiri (1.19.1-aarch64-linux-gnu)
       racc (~> 1.4)
     nokogiri (1.19.1-arm64-darwin)
@@ -368,20 +372,20 @@ GEM
     rack-timeout (0.7.0)
     rackup (2.3.1)
       rack (>= 3)
-    rails (8.0.3)
-      actioncable (= 8.0.3)
-      actionmailbox (= 8.0.3)
-      actionmailer (= 8.0.3)
-      actionpack (= 8.0.3)
-      actiontext (= 8.0.3)
-      actionview (= 8.0.3)
-      activejob (= 8.0.3)
-      activemodel (= 8.0.3)
-      activerecord (= 8.0.3)
-      activestorage (= 8.0.3)
-      activesupport (= 8.0.3)
+    rails (8.1.2)
+      actioncable (= 8.1.2)
+      actionmailbox (= 8.1.2)
+      actionmailer (= 8.1.2)
+      actionpack (= 8.1.2)
+      actiontext (= 8.1.2)
+      actionview (= 8.1.2)
+      activejob (= 8.1.2)
+      activemodel (= 8.1.2)
+      activerecord (= 8.1.2)
+      activestorage (= 8.1.2)
+      activesupport (= 8.1.2)
       bundler (>= 1.15.0)
-      railties (= 8.0.3)
+      railties (= 8.1.2)
     rails-dom-testing (2.3.0)
       activesupport (>= 5.0.0)
       minitest
@@ -396,9 +400,9 @@ GEM
       json (>= 1.7, < 3)
       rails
       rubyzip (~> 2)
-    railties (8.0.3)
-      actionpack (= 8.0.3)
-      activesupport (= 8.0.3)
+    railties (8.1.2)
+      actionpack (= 8.1.2)
+      activesupport (= 8.1.2)
       irb (~> 1.13)
       rackup (>= 1.0.0)
       rake (>= 12.2)
@@ -407,7 +411,7 @@ GEM
       zeitwerk (~> 2.6)
     rainbow (3.1.1)
     rake (13.3.1)
-    rdoc (7.0.3)
+    rdoc (7.2.0)
       erb
       psych (>= 4.0.0)
       tsort
@@ -529,9 +533,9 @@ GEM
       railties (>= 6.0.0)
     stringio (3.2.0)
     temple (0.10.4)
-    thor (1.4.0)
+    thor (1.5.0)
     tilt (2.6.1)
-    timeout (0.4.4)
+    timeout (0.6.0)
     tsort (0.2.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
@@ -559,7 +563,7 @@ GEM
     xpath (3.2.0)
       nokogiri (~> 1.8)
     zache (0.13.2)
-    zeitwerk (2.7.4)
+    zeitwerk (2.7.5)
 
 PLATFORMS
   aarch64-linux
@@ -606,7 +610,7 @@ DEPENDENCIES
   puma
   rack-cors
   rack-timeout
-  rails (~> 8.0.3)
+  rails (~> 8.1.2)
   rails-i18n
   rails_real_favicon
   ridgepole
diff --git a/spec/mailers/song_mailer_spec.rb b/spec/mailers/song_mailer_spec.rb
index e99278ee7..b86802629 100644
--- a/spec/mailers/song_mailer_spec.rb
+++ b/spec/mailers/song_mailer_spec.rb
@@ -25,7 +25,7 @@
       expect(mail.from).to contain_exactly 'noreply@livelog.ku-unplugged.net'
       expect(mail.bcc).to match_array users.map(&:email)
       expect(mail.subject).to eq '「くちなしの丘」が今日のピックアップに選ばれました！'
-      expect(mail.body.to_s).to eq read_fixture('pickup.txt').gsub("\n", "\r\n")
+      expect(mail.body.to_s.gsub("\r\n", "\n")).to eq read_fixture('pickup.txt')
     end
   end
 end