diff --git a/.github/workflows/actions.yml b/.github/workflows/actions.yml
index 41067917..3e249109 100644
--- a/.github/workflows/actions.yml
+++ b/.github/workflows/actions.yml
@@ -28,10 +28,10 @@ jobs:
       - name: Yarn Audit welcome
         run: yarn audit --level high --groups dependencies
         working-directory: welcome
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'adopt'
           cache: 'maven'
       - name: Set up MySQL
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index b086d3d4..cf25786d 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -51,10 +51,10 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'adopt'
 
       # Initializes the CodeQL tools for scanning.
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 400db5e9..f2a40582 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -26,7 +26,7 @@ jobs:
 
       - uses: actions/setup-java@v4
         with:
-          java-version: 17
+          java-version: 21
           distribution: "temurin"
 
       - name: Set up cache
@@ -53,10 +53,10 @@ jobs:
           exit 1
         if: github.event_name != 'workflow_dispatch' && steps.versioncheck.outputs.version != github.ref_name
 
-      - name: Set up JDK 17 for snapshots
+      - name: Set up JDK 21 for snapshots
         uses: actions/setup-java@v4
         with:
-          java-version: "17"
+          java-version: "21"
           distribution: "temurin"
           cache: "maven"
           server-id: openconext-snapshots
@@ -64,10 +64,10 @@ jobs:
           server-password: MAVEN_PASSWORD
         if: ( endsWith(steps.versioncheck.outputs.version, '-SNAPSHOT'))
 
-      - name: Set up JDK 17 for releases
+      - name: Set up JDK 21 for releases
         uses: actions/setup-java@v4
         with:
-          java-version: "17"
+          java-version: "21"
           distribution: "temurin"
           cache: "maven"
           server-id: openconext-releases
diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
index ea5a7b60..3d41d1a2 100644
--- a/.github/workflows/doc.yml
+++ b/.github/workflows/doc.yml
@@ -41,10 +41,10 @@ jobs:
               - 'server/src/**'
 
       # Generate the OpenApi spec json, only if the server component has changes
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v2
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'adopt'
           cache: 'maven'
         if: ${{ steps.changes.outputs.server == 'true' ||  github.event_name == 'workflow_dispatch' }}
diff --git a/README.md b/README.md
index 753f6c21..7bd1e1fc 100644
--- a/README.md
+++ b/README.md
@@ -8,14 +8,14 @@
 
 ### [System Requirements](#system-requirements)
 
-- Java 17
+- Java 21
 - Maven 3
 
-First install Java 17 with a package manager
+First install Java 21 with a package manager
 and then export the correct the `JAVA_HOME`. For example on macOS:
 
 ```bash
-export JAVA_HOME=/Library/Java/JavaVirtualMachines/openjdk-17.jdk/Contents/Home/
+export JAVA_HOME=/Library/Java/JavaVirtualMachines/openjdk-21.jdk/Contents/Home/
 ```
 
 Then create the MySQL database:
diff --git a/pom.xml b/pom.xml
index 2b354f9a..ce830bf5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -16,7 +16,7 @@
     </parent>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <java.version>17</java.version>
+        <java.version>21</java.version>
     </properties>
     <modules>
         <module>server</module>
@@ -31,7 +31,7 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.13.0</version>
                 <configuration>
-                    <release>17</release>
+                    <release>21</release>
                 </configuration>
             </plugin>
             <plugin>
@@ -50,7 +50,7 @@
                                     <version>[3.8.7,)</version>
                                 </requireMavenVersion>
                                 <requireJavaVersion>
-                                    <version>17</version>
+                                    <version>21</version>
                                 </requireJavaVersion>
                             </rules>
                         </configuration>
diff --git a/provisioning-mock/docker/Dockerfile b/provisioning-mock/docker/Dockerfile
index 1988dc55..0b652436 100644
--- a/provisioning-mock/docker/Dockerfile
+++ b/provisioning-mock/docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jdk-alpine
+FROM eclipse-temurin:21-jdk-alpine
 COPY target/*.jar app.jar
 ENTRYPOINT ["java","-jar","/app.jar"]
 
diff --git a/server/docker/Dockerfile b/server/docker/Dockerfile
index 1988dc55..0b652436 100644
--- a/server/docker/Dockerfile
+++ b/server/docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jdk-alpine
+FROM eclipse-temurin:21-jdk-alpine
 COPY target/*.jar app.jar
 ENTRYPOINT ["java","-jar","/app.jar"]