diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c637669..984ca7c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu]
-        ruby: ['3.4', '3.3', '3.2', '3.1', '3.0', '2.7']
+        ruby: ['4.0', '3.4', '3.3', '3.2', '3.1', '3.0', '2.7']
 
     steps:
     - uses: actions/checkout@v4