diff --git a/.github/workflows/ci-manual.yml b/.github/workflows/ci-manual.yml
index c53a431..a923916 100644
--- a/.github/workflows/ci-manual.yml
+++ b/.github/workflows/ci-manual.yml
@@ -35,6 +35,7 @@ on:
         options:
           - 11
           - 17
+          - 21
 
 jobs:
   build-test:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 30d238b..5a39662 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest]
         jdk-distribution: [temurin, adopt-openj9]
-        jdk-version: [11, 17]
+        jdk-version: [11, 17, 21]
     steps:
     - name: Configure runner - Linux 
       if: contains(matrix.os, 'ubuntu')