diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e282e49..f622ca2 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["3.1", "3.2", "3.3", "3.4", "jruby"]
+        ruby: ["3.1", "3.2", "3.3", "3.4", "4.0", "jruby"]
 
     steps:
       - name: Checkout code