diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e509e0b9..3d99a8a1 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -30,7 +30,8 @@ jobs:
         java: [
           { 'version': '11', 'opts': '-Drevapi.skip' },
           { 'version': '17', 'opts': 'javadoc:javadoc' },
-          { 'version': '20', 'opts': '-Drevapi.skip' }
+          { 'version': '20', 'opts': 'javadoc:javadoc' },
+          { 'version': '21', 'opts': '-Drevapi.skip' }
         ]
     name: build with jdk ${{matrix.java.version}}
 
@@ -55,7 +56,8 @@ jobs:
         java: [
           { 'version': '11', 'opts': '' },
           { 'version': '17', 'opts': '' },
-          { 'version': '20', 'opts': '' }
+          { 'version': '20', 'opts': '' },
+          { 'version': '21', 'opts': '' }
         ]
     name: build with jdk ${{matrix.java.version}} windows
 
@@ -81,7 +83,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v3
         with:
-          java-version: 17
+          java-version: 21
           distribution: temurin
           cache: maven
       - name: Compatibility Check
@@ -100,7 +102,7 @@ jobs:
       - uses: actions/setup-java@v3
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
           cache: maven
 
       - name: sonar
diff --git a/.github/workflows/post-release.yml b/.github/workflows/post-release.yml
index 3d61c174..acb1ecda 100644
--- a/.github/workflows/post-release.yml
+++ b/.github/workflows/post-release.yml
@@ -15,9 +15,9 @@ jobs:
         with:
           fetch-depth: 0 # fetch all commits and branches for mike to work properly
       - uses: actions/setup-java@v3
-        name: Set up Java 17
+        name: Set up Java 21
         with:
-          java-version: 17
+          java-version: 21
           distribution: temurin
           cache: maven       
       - name: Build local artifacts
diff --git a/.github/workflows/website.yml b/.github/workflows/website.yml
index ab2eec97..056e276e 100644
--- a/.github/workflows/website.yml
+++ b/.github/workflows/website.yml
@@ -15,9 +15,9 @@ jobs:
         with:
           fetch-depth: 0 # fetch all commits and branches for mike to work properly
       - uses: actions/setup-java@v3
-        name: Set up Java 17
+        name: Set up Java 21
         with:
-          java-version: 17
+          java-version: 21
           distribution: temurin
           cache: maven
       - uses: actions/setup-python@v4