diff --git a/.github/workflows/downstream.yml b/.github/workflows/downstream.yml
index ffb82d0..7ca7b1e 100644
--- a/.github/workflows/downstream.yml
+++ b/.github/workflows/downstream.yml
@@ -25,16 +25,19 @@ jobs:
       matrix:
         include:
           - url: https://github.com/rails/tailwindcss-rails
-            name: tailwindcss-rails
+            name: rails-unit
             command: "bin/test"
             ruby: "3.3"
+          - url: https://github.com/rails/tailwindcss-rails
+            name: rails-integration
+            command: "env TAILWINDCSSOPTS=--path=../../.. test/integration/user_journey_test.sh"
+            ruby: "3.3"
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.ruby}}
-      - run: gem install bundler -v ">= 2.3.22" # for "add --path"
       - run: bundle install --local || bundle install
       - run: bundle exec rake download
       - run: git clone --depth=1 ${{matrix.url}} ${{matrix.name}}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4838e2e..1872205 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## [Unreleased]
 
+## v3.4.15
+
+* Update `tailwindcss` to [v3.4.15](https://github.com/tailwindlabs/tailwindcss/releases/tag/v3.4.15). (#19) @flavorjones
+
+
 ## v3.4.14
 
 * Update `tailwindcss` to [v3.4.14](https://github.com/tailwindlabs/tailwindcss/releases/tag/v3.4.14). (#8) @flavorjones
diff --git a/Gemfile.lock b/Gemfile.lock
index 7d0cc59..327ea8e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    tailwindcss-ruby (3.4.14)
+    tailwindcss-ruby (3.4.15)
 
 GEM
   remote: https://rubygems.org/
@@ -35,7 +35,7 @@ GEM
       rubocop (>= 1.48.1, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
     ruby-progressbar (1.13.0)
-    standard (1.41.0)
+    standard (1.41.1)
       language_server-protocol (~> 3.17.0.2)
       lint_roller (~> 1.0)
       rubocop (~> 1.66.0)
diff --git a/lib/tailwindcss/ruby/upstream.rb b/lib/tailwindcss/ruby/upstream.rb
index aa23e2c..e2260d6 100644
--- a/lib/tailwindcss/ruby/upstream.rb
+++ b/lib/tailwindcss/ruby/upstream.rb
@@ -1,7 +1,7 @@
 module Tailwindcss
   module Ruby
     module Upstream
-      VERSION = "v3.4.14"
+      VERSION = "v3.4.15"
 
       # rubygems platform name => upstream release filename
       NATIVE_PLATFORMS = {
diff --git a/lib/tailwindcss/ruby/version.rb b/lib/tailwindcss/ruby/version.rb
index f0db692..2955318 100644
--- a/lib/tailwindcss/ruby/version.rb
+++ b/lib/tailwindcss/ruby/version.rb
@@ -2,6 +2,6 @@
 
 module Tailwindcss
   module Ruby
-    VERSION = "3.4.14"
+    VERSION = "3.4.15"
   end
 end