diff --git a/.github/old-workflows/check-pr-style.yml b/.github/old-workflows/check-pr-style.yml
index 7406bef33..9e0568f90 100644
--- a/.github/old-workflows/check-pr-style.yml
+++ b/.github/old-workflows/check-pr-style.yml
@@ -11,10 +11,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v1
       with:
-        java-version: 17
+        java-version: 21
     - name: Run java checkstyle
       uses: nikitasavinov/checkstyle-action@0.3.1
       with:
diff --git a/.github/workflows/javadoc.yml b/.github/workflows/javadoc.yml
index ff2e4c643..92d41fb98 100644
--- a/.github/workflows/javadoc.yml
+++ b/.github/workflows/javadoc.yml
@@ -11,10 +11,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v1
         with:
-          java-version: 17
+          java-version: 21
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew
       - name: Build javadoc
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 50ffb53a5..851212ef4 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -9,11 +9,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v2
       with:
         distribution: 'zulu'
-        java-version: 17
+        java-version: 21
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Setup gradle cache
@@ -40,10 +40,10 @@ jobs:
       GPG_PASSPHRASE: ${{ secrets.GPG_PASSWORD }}
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v2
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
       - name: Set outputs
         id: vars
diff --git a/.github/workflows/snapshot-deploy.yaml b/.github/workflows/snapshot-deploy.yaml
index 3eefeee1f..cf032b8da 100644
--- a/.github/workflows/snapshot-deploy.yaml
+++ b/.github/workflows/snapshot-deploy.yaml
@@ -14,10 +14,10 @@ jobs:
       GPG_PASSPHRASE: ${{ secrets.GPG_PASSWORD }}
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v2
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
       - name: Set outputs
         id: vars
diff --git a/build.gradle.kts b/build.gradle.kts
index ffb459801..7140bb97d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -36,8 +36,8 @@ allprojects {
         withSourcesJar()
         withJavadocJar()
 
-        sourceCompatibility = JavaVersion.VERSION_17
-        targetCompatibility = JavaVersion.VERSION_17
+        sourceCompatibility = JavaVersion.VERSION_21
+        targetCompatibility = JavaVersion.VERSION_21
     }
 
     tasks.withType<Zip> {
@@ -101,9 +101,9 @@ tasks {
 
             // Custom options
             addBooleanOption("html5", true)
-            addStringOption("-release", "17")
+            addStringOption("-release", "21")
             // Links to external javadocs
-            links("https://docs.oracle.com/en/java/javase/17/docs/api/")
+            links("https://docs.oracle.com/en/java/javase/21/docs/api/")
             links("https://jd.adventure.kyori.net/api/${libs.versions.adventure.get()}/")
         }
     }
diff --git a/jitpack.yml b/jitpack.yml
index 1e41e00b7..a20279256 100644
--- a/jitpack.yml
+++ b/jitpack.yml
@@ -1,2 +1,2 @@
 jdk:
-  - openjdk17
\ No newline at end of file
+  - openjdk21
\ No newline at end of file