diff --git a/build.gradle b/build.gradle
index 64064a6..bc335ed 100644
--- a/build.gradle
+++ b/build.gradle
@@ -12,13 +12,6 @@ allprojects {
         mavenCentral()
     }
 
-    tasks.withType(JavaCompile).tap {
-        configureEach {
-            sourceCompatibility = JavaVersion.VERSION_1_8
-            targetCompatibility = JavaVersion.VERSION_1_8
-        }
-    }
-
     tasks.withType(Jar).tap {
         configureEach {
             from(project.rootDir) {
diff --git a/example/build.gradle b/example/build.gradle
index a79cec1..b7e816a 100644
--- a/example/build.gradle
+++ b/example/build.gradle
@@ -2,8 +2,10 @@ plugins {
     id 'application'
 }
 
-repositories {
-    mavenCentral()
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
 }
 
 application {
diff --git a/imgui-app/build.gradle b/imgui-app/build.gradle
index ee0eaf4..e67c105 100644
--- a/imgui-app/build.gradle
+++ b/imgui-app/build.gradle
@@ -1,13 +1,15 @@
 plugins {
     id 'java-library'
-    id 'com.github.johnrengelman.shadow' version '7.0.0'
+    id 'com.github.johnrengelman.shadow' version '7.1.2'
     id 'checkstyle'
     id 'maven-publish'
     id 'signing'
 }
 
-repositories {
-    mavenCentral()
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
 }
 
 dependencies {
@@ -44,7 +46,6 @@ jar {
 
 shadowJar {
     with jar
-    archiveClassifier.set(null)
 }
 
 apply from: "$rootDir/publish.gradle"
diff --git a/imgui-binding-natives/build.gradle b/imgui-binding-natives/build.gradle
index 4d3eb55..0864907 100644
--- a/imgui-binding-natives/build.gradle
+++ b/imgui-binding-natives/build.gradle
@@ -4,6 +4,12 @@ plugins {
     id 'signing'
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
+}
+
 def packageName = 'imgui-java-natives-linux'
 def packageDesc = 'Native binaries for imgui-java binding for Linux'
 def moduleName = 'imgui.natives.linux'
diff --git a/imgui-binding/build.gradle b/imgui-binding/build.gradle
index b28535c..3b834ad 100644
--- a/imgui-binding/build.gradle
+++ b/imgui-binding/build.gradle
@@ -7,6 +7,12 @@ plugins {
     id 'signing'
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
+}
+
 dependencies {
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.5.2'
     testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.5.2'
diff --git a/imgui-lwjgl3/build.gradle b/imgui-lwjgl3/build.gradle
index d39a696..af31358 100644
--- a/imgui-lwjgl3/build.gradle
+++ b/imgui-lwjgl3/build.gradle
@@ -5,6 +5,12 @@ plugins {
     id 'signing'
 }
 
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+    }
+}
+
 dependencies {
     implementation platform("org.lwjgl:lwjgl-bom:$lwjglVersion")