diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 5e2f91f..847c06a 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -22,10 +22,10 @@ jobs:
 
     steps:
     - 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: 'temurin'
 
     # Configure Gradle for optimal use in GitHub Actions, including caching of downloaded dependencies.
@@ -55,10 +55,10 @@ jobs:
 
     steps:
     - 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: 'temurin'
 
     # Generates and submits a dependency graph, enabling Dependabot Alerts for all project dependencies.
diff --git a/Dockerfile b/Dockerfile
index 8d1d7a8..3e0f4cc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17.0.14_7-jre-alpine
+FROM eclipse-temurin:21.0.8_9-jre-alpine
 
 LABEL maintainer="Bertrik Sikken bertrik@gmail.com"
 LABEL org.opencontainers.image.source="https://github.com/bertrik/energymix-server"
diff --git a/build.gradle b/build.gradle
index a2403b8..bbfffb6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -20,8 +20,8 @@ subprojects {
     apply plugin: 'net.ltgt.errorprone'
 
     java {
-        targetCompatibility = JavaVersion.VERSION_17
-        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_21
+        sourceCompatibility = JavaVersion.VERSION_21
     }
 
     repositories {
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c7bd474..418012d 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -3,7 +3,7 @@ jackson = "2.20.0"
 junit = "6.0.0"
 retrofit = "3.0.0"
 dropwizard = "5.0.0"
-errorprone = "2.42.0"
+errorprone = "2.43.0"
 
 [libraries]
 errorprone_annotations = { module = "com.google.errorprone:error_prone_annotations", version.ref = "errorprone" }