diff --git a/.github/workflows/build-develop.yml b/.github/workflows/build-develop.yml
index 00b200d..ec24a01 100644
--- a/.github/workflows/build-develop.yml
+++ b/.github/workflows/build-develop.yml
@@ -22,7 +22,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Gradle Caching
         uses: actions/cache@v3
         with:
@@ -48,7 +48,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Gradle Caching
         uses: actions/cache@v3
         with:
@@ -74,7 +74,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Gradle Caching
         uses: actions/cache@v3
         with:
@@ -115,7 +115,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Gradle Caching
         uses: actions/cache@v3
         with:
diff --git a/.github/workflows/build-main.yml b/.github/workflows/build-main.yml
index 5e1e655..e026a21 100644
--- a/.github/workflows/build-main.yml
+++ b/.github/workflows/build-main.yml
@@ -13,7 +13,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Gradle Caching
         uses: actions/cache@v3
         with:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index b7c679e..8c613f8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -17,7 +17,7 @@ jobs:
         uses: actions/setup-java@v3
         with:
           distribution: 'zulu'
-          java-version: '17'
+          java-version: '21'
       - name: Extract tag version
         run: echo "tag=$(echo '${{ github.ref_name }}' | egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}(-p[0-9]+)?')" >> $GITHUB_OUTPUT
         id: extract_tag_version
diff --git a/build.gradle.kts b/build.gradle.kts
index 87f353a..4fa8b9c 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,6 +1,7 @@
 plugins {
     idea
     id("net.researchgate.release") version "3.0.2"
+    kotlin("jvm") version "1.9.24" apply false
 }
 
 allprojects {
diff --git a/doc/installation.md b/doc/installation.md
index 7c11ffc..1372cce 100644
--- a/doc/installation.md
+++ b/doc/installation.md
@@ -3,7 +3,7 @@
 ## Prerequisite
 
 - Scavenger is a combination of various server components(API, Frontend, Collector) and agent component.
-  To install scavenger, you need JDK 17 or latest version.
+  To install scavenger, you need JDK 21 or latest version.
 - Scavenger uses 2 ports. if some ports are blocked by your firewall, you should ask the network admin to open the
   following ports in the firewall.
   These ports can be configured by the configuration.
diff --git a/scavenger-api/build.gradle.kts b/scavenger-api/build.gradle.kts
index 73a416a..ed12912 100644
--- a/scavenger-api/build.gradle.kts
+++ b/scavenger-api/build.gradle.kts
@@ -54,7 +54,7 @@ configure<DependencyManagementExtension> {
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 tasks.withType<KotlinCompile> {
diff --git a/scavenger-collector/build.gradle.kts b/scavenger-collector/build.gradle.kts
index a664957..4ca9f36 100644
--- a/scavenger-collector/build.gradle.kts
+++ b/scavenger-collector/build.gradle.kts
@@ -69,7 +69,7 @@ configure<DependencyManagementExtension> {
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 tasks.withType<KotlinCompile> {
diff --git a/scavenger-demo-extension/build.gradle.kts b/scavenger-demo-extension/build.gradle.kts
index 8700146..3676d58 100644
--- a/scavenger-demo-extension/build.gradle.kts
+++ b/scavenger-demo-extension/build.gradle.kts
@@ -15,7 +15,7 @@ dependencies {
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 tasks.withType<KotlinCompile> {
diff --git a/scavenger-demo/build.gradle.kts b/scavenger-demo/build.gradle.kts
index 82ab238..d3dcc28 100644
--- a/scavenger-demo/build.gradle.kts
+++ b/scavenger-demo/build.gradle.kts
@@ -29,7 +29,7 @@ dependencies {
 }
 
 kotlin {
-    jvmToolchain(17)
+    jvmToolchain(21)
 }
 
 tasks.withType<KotlinCompile> {
diff --git a/scavenger-entity/build.gradle.kts b/scavenger-entity/build.gradle.kts
index 362f406..75b3f45 100644
--- a/scavenger-entity/build.gradle.kts
+++ b/scavenger-entity/build.gradle.kts
@@ -13,7 +13,7 @@ dependencies {
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(17))
+        languageVersion.set(JavaLanguageVersion.of(21))
     }
 }
 
diff --git a/scavenger-old-agent-java/build.gradle.kts b/scavenger-old-agent-java/build.gradle.kts
index 5042545..80716ad 100644
--- a/scavenger-old-agent-java/build.gradle.kts
+++ b/scavenger-old-agent-java/build.gradle.kts
@@ -36,6 +36,9 @@ dependencies {
 java {
     withJavadocJar()
     withSourcesJar()
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
 }
 
 tasks.compileJava {
diff --git a/scavenger-old-model/build.gradle.kts b/scavenger-old-model/build.gradle.kts
index 452fefe..2eeb8d7 100644
--- a/scavenger-old-model/build.gradle.kts
+++ b/scavenger-old-model/build.gradle.kts
@@ -15,6 +15,12 @@ dependencies {
     testImplementation("org.hamcrest:hamcrest:2.2")
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
+}
+
 tasks.compileJava {
     sourceCompatibility = "7"
     targetCompatibility = "7"