diff --git a/.github/workflows/build-main.yml b/.github/workflows/build-main.yml
index 92872c3..00833cd 100644
--- a/.github/workflows/build-main.yml
+++ b/.github/workflows/build-main.yml
@@ -13,7 +13,8 @@ jobs:
       matrix:
         java: [
           { 'version': '11', 'opts': '' },
-          { 'version': '17', 'opts': '' }
+          { 'version': '17', 'opts': '' },
+          { 'version': '21', 'opts': '' }
         ]
     name: Build with Java ${{ matrix.java.version }} (OpenJDK)
     steps:
diff --git a/.github/workflows/build-pull-request.yml b/.github/workflows/build-pull-request.yml
index 983392b..8612c6a 100644
--- a/.github/workflows/build-pull-request.yml
+++ b/.github/workflows/build-pull-request.yml
@@ -9,7 +9,8 @@ jobs:
       matrix:
         java: [
           { 'version': '11', 'opts': '' },
-          { 'version': '17', 'opts': '' }
+          { 'version': '17', 'opts': '' },
+          { 'version': '21', 'opts': '' }
         ]
     name: Build with Java ${{ matrix.java.version }} (OpenJDK)
     steps: