diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a9aa41c..52e7a53 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,23 +1,30 @@
 name: Java CI
 
-on: [push, pull_request]
+on:
+  push:
+    branches: [ main ]
+  pull_request: {}
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
-    - name: Set up JDK 1.8
-      uses: actions/setup-java@v1
+    - uses: actions/checkout@v5
+
+    - uses: actions/setup-java@v5
       with:
-        java-version: 1.8
-    - name: Grant execute permission
-      run: chmod +x gradlew
+        java-version: 17
+        distribution: zulu
+
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4
+
     - name: Build with Gradle
       run: ./gradlew -Pversion="" build
+
     - name: Upload artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v4
       with:
         name: Jars
         path: build/libs/
diff --git a/build.gradle b/build.gradle
deleted file mode 100644
index 5c49758..0000000
--- a/build.gradle
+++ /dev/null
@@ -1,76 +0,0 @@
-plugins {
-    id 'java'
-    id "me.champeau.jmh" version "0.7.3"
-    id 'com.github.johnrengelman.shadow' version '8.1.1'
-}
-
-repositories {
-    mavenCentral()
-}
-
-build.dependsOn shadowJar
-
-version = "1.6.0"
-group = "me.towdium.pinin"
-
-shadowJar {
-    exclude 'it/unimi/dsi/fastutil/shorts/**'
-    exclude 'it/unimi/dsi/fastutil/longs/**'
-    exclude 'it/unimi/dsi/fastutil/floats/**'
-    exclude 'it/unimi/dsi/fastutil/doubles/**'
-    exclude 'it/unimi/dsi/fastutil/bytes/**'
-    exclude 'it/unimi/dsi/fastutil/booleans/**'
-    exclude 'it/unimi/dsi/fastutil/ints/*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Short*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Reference*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Long*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Int*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Float*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Double*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Char*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Byte*Map*'
-    exclude 'it/unimi/dsi/fastutil/objects/*2Boolean*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Short*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Reference*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Long*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Int*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Float*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Double*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Char*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Byte*Map*'
-    exclude 'it/unimi/dsi/fastutil/chars/*2Boolean*Map*'
-    relocate 'it.unimi.dsi.fastutil', 'me.towdium.pinin.fastutil'
-}
-
-test {
-    useJUnitPlatform()
-    dependsOn cleanTest
-    testLogging.showStandardStreams = true
-}
-
-tasks.withType(JavaCompile).configureEach {
-    options.encoding = "UTF-8"
-}
-
-dependencies {
-    implementation 'it.unimi.dsi:fastutil:8.3.0'
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.7.1'
-    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-    testImplementation 'org.openjdk.jol:jol-core:0.17'
-    jmhImplementation 'org.openjdk.jmh:jmh-generator-annprocess:1.37'
-    jmhAnnotationProcessor 'org.openjdk.jmh:jmh-generator-annprocess:1.37'
-}
-
-jmh {
-    resultFormat = 'JSON'
-}
-
-tasks.compileJmhJava {
-    sourceCompatibility = '1.8'
-    targetCompatibility = '1.8'
-}
-
-compileJava {
-    sourceCompatibility = '1.8'
-    targetCompatibility = '1.8'
-}
diff --git a/build.gradle.kts b/build.gradle.kts
new file mode 100644
index 0000000..383ee7b
--- /dev/null
+++ b/build.gradle.kts
@@ -0,0 +1,73 @@
+plugins {
+    java
+    id("me.champeau.jmh") version "0.7.3"
+    id("com.gradleup.shadow") version "9.2.0"
+}
+
+group = "me.towdium.pinin"
+version = "1.6.0"
+
+repositories {
+    mavenCentral()
+}
+
+tasks.build {
+    dependsOn(tasks.shadowJar)
+}
+
+tasks.shadowJar {
+    exclude("it/unimi/dsi/fastutil/shorts/**")
+    exclude("it/unimi/dsi/fastutil/longs/**")
+    exclude("it/unimi/dsi/fastutil/floats/**")
+    exclude("it/unimi/dsi/fastutil/doubles/**")
+    exclude("it/unimi/dsi/fastutil/bytes/**")
+    exclude("it/unimi/dsi/fastutil/booleans/**")
+    exclude("it/unimi/dsi/fastutil/ints/*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Short*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Reference*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Long*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Int*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Float*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Double*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Char*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Byte*Map*")
+    exclude("it/unimi/dsi/fastutil/objects/*2Boolean*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Short*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Reference*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Long*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Int*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Float*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Double*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Char*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Byte*Map*")
+    exclude("it/unimi/dsi/fastutil/chars/*2Boolean*Map*")
+    relocate("it.unimi.dsi.fastutil", "me.towdium.pinin.fastutil")
+}
+
+jmh {
+    resultFormat = "JSON"
+}
+
+tasks.test {
+    useJUnitPlatform()
+    testLogging.showStandardStreams = true
+}
+
+tasks.withType<JavaCompile> {
+    options.encoding = "UTF-8"
+    options.release = 8
+}
+
+dependencies {
+    implementation("it.unimi.dsi:fastutil:8.3.0")
+    testImplementation("org.junit.jupiter:junit-jupiter:5.7.1")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+    testImplementation("org.openjdk.jol:jol-core:0.17")
+    jmhImplementation("org.openjdk.jmh:jmh-generator-annprocess:1.37")
+    jmhAnnotationProcessor("org.openjdk.jmh:jmh-generator-annprocess:1.37")
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
diff --git a/src/test/java/me/towdium/pinin/CharLayoutTest.java b/src/test/java/me/towdium/pinin/CharLayoutTest.java
index 960fb37..7e4e27b 100644
--- a/src/test/java/me/towdium/pinin/CharLayoutTest.java
+++ b/src/test/java/me/towdium/pinin/CharLayoutTest.java
@@ -11,10 +11,10 @@ public class CharLayoutTest {
 
     @Test
     public void layout() {
-        var intBased = ClassLayout.parseClass(CharInt.class);
+        ClassLayout intBased = ClassLayout.parseClass(CharInt.class);
         System.out.println(intBased.toPrintable());
 
-        var charBased = ClassLayout.parseClass(CharChar.class);
+        ClassLayout charBased = ClassLayout.parseClass(CharChar.class);
         System.out.println(charBased.toPrintable());
 
         Assertions.assertEquals(intBased.instanceSize(), charBased.instanceSize());