diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 2c6dd48..bed5eba 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ 8, 11, 17 ]
+        java: [ 8, 11, 17, 21 ]
     name: Java ${{matrix.java}}
     steps:
       - uses: actions/checkout@v2