diff --git a/.github/workflows/deploy_snapshot.yml b/.github/workflows/deploy_snapshot.yml
index db4c6e3..7380b9f 100644
--- a/.github/workflows/deploy_snapshot.yml
+++ b/.github/workflows/deploy_snapshot.yml
@@ -15,7 +15,7 @@ on:
     types: [ trigger_after_upstream_deploy ]
 
 env:
-  GRADLE_VERSION: 7.6 # Gradle version used
+  GRADLE_VERSION: 8.5 # Gradle version used
   GRADLE_CLI_OPTS: "-Pci --build-cache --refresh-dependencies " # CLI options passed to Gradle
   GRADLE_BUILD_ACTION_CACHE_KEY_JOB: "test-cache-${{ github.head_ref }}.${{ github.sha }}"
 
@@ -29,6 +29,11 @@ jobs:
     steps:
       - name: Checkout project sources
         uses: actions/checkout@v4
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
         with:
@@ -45,6 +50,11 @@ jobs:
     steps:
       - name: Checkout project sources
         uses: actions/checkout@v4
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
         with:
diff --git a/.github/workflows/test_branch.yml b/.github/workflows/test_branch.yml
index 8491a29..698cec6 100644
--- a/.github/workflows/test_branch.yml
+++ b/.github/workflows/test_branch.yml
@@ -12,7 +12,7 @@ on:
     branches-ignore: [ "dev" ] # Do not run this on the default branch
 
 env:
-  GRADLE_VERSION: 7.6 # Gradle version used
+  GRADLE_VERSION: 8.5 # Gradle version used
   GRADLE_CLI_OPTS: "-Pci --build-cache --refresh-dependencies " # CLI options passed to Gradle
   GRADLE_BUILD_ACTION_CACHE_KEY_JOB: "test-cache-${{ github.head_ref }}.${{ github.sha }}"
 
@@ -26,6 +26,11 @@ jobs:
     steps:
       - name: Checkout project sources
         uses: actions/checkout@v4
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
       - name: Setup Gradle
         uses: gradle/actions/setup-gradle@v4
         with:
diff --git a/WorkflowCLI/build.gradle b/WorkflowCLI/build.gradle
index f55ff5b..0271841 100644
--- a/WorkflowCLI/build.gradle
+++ b/WorkflowCLI/build.gradle
@@ -1,6 +1,6 @@
 plugins {
     id "java-library"
-    id "com.github.johnrengelman.shadow" version "7.1.2"
+    id 'com.gradleup.shadow' version "8.3.9"
     id "jacoco"
     id "de.se_rwth.codestyle" version "$mc_version"
 }
diff --git a/build.gradle b/build.gradle
index 9e9dd75..5a89958 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,11 +4,14 @@ import org.gradle.api.tasks.testing.logging.TestLogEvent
 
 
 plugins {
+    id 'java'
     id "maven-publish"
     id "io.github.themrmilchmann.ecj" version "0.2.0" apply false
     id "de.se_rwth.codestyle" version "$mc_version"
 }
 
+
+
 description = "BPMN-DSL"
 
 allprojects {
@@ -33,6 +36,10 @@ subprojects {
     apply plugin: 'io.github.themrmilchmann.ecj'
     apply plugin: 'maven-publish'
 
+    ecj {
+        compilerVersion = "3.43.0"
+    }
+
     tasks.withType(Test).configureEach {
         useJUnit()
         testLogging {
@@ -67,8 +74,8 @@ subprojects {
 
     tasks.withType(JavaCompile).tap {
         configureEach {
-            sourceCompatibility = JavaVersion.VERSION_11
-            targetCompatibility = JavaVersion.VERSION_11
+            sourceCompatibility = JavaVersion.VERSION_21
+            targetCompatibility = JavaVersion.VERSION_21
             options.encoding = "UTF-8"
             options.deprecation false
             options.warnings = false