diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c4edd11..c949340 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -18,11 +18,16 @@ jobs:
           - gemfiles/Gemfile.activesupport-6.x
           - gemfiles/Gemfile.activesupport-7.1.x
           - gemfiles/Gemfile.activesupport-7.2.x
+          - gemfiles/Gemfile.activesupport-8.x
         exclude:
             - gemfile: gemfiles/Gemfile.activesupport-7.2.x
-              ruby_version: 2.7.8
-            - gemfile: gemfiles/Gemfile.activesupport-7.2.x
-              ruby_version: 3.0.7
+              ruby_version:
+                - 2.7.8
+                - 3.0.7
+            - gemfile: gemfiles/Gemfile.activesupport-8.x
+              ruby_version:
+                - 2.7.8
+                - 3.0.7
     env:
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     steps:
diff --git a/gemfiles/Gemfile.activesupport-8.x b/gemfiles/Gemfile.activesupport-8.x
new file mode 100644
index 0000000..82ce184
--- /dev/null
+++ b/gemfiles/Gemfile.activesupport-8.x
@@ -0,0 +1,5 @@
+source 'https://rubygems.org'
+
+gemspec :path => '..'
+
+gem 'activesupport', '~> 8.0'