diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b428b17..fea99bd 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ 11, 17 ]
+        java: [ 11, 17, 21 ]
     name: Build with JDK ${{matrix.java}}
 
     steps: