diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 4d0f301..bb1f0c3 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.2', '3.3', '3.4', 'jruby-10.0']
+        ruby: ['3.2', '3.3', '3.4', '4.0', 'jruby-10.0']
     env:
       BUNDLE_WITHOUT: optional
     steps: