diff --git a/ant/build.gradle b/ant/build.gradle
index f1d8c2c1..1473ab2d 100644
--- a/ant/build.gradle
+++ b/ant/build.gradle
@@ -1,7 +1,7 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 
 plugins {
-    id 'com.github.johnrengelman.shadow'
+    id 'com.gradleup.shadow'
     id 'java'
     id 'maven-publish'
 }
@@ -15,21 +15,17 @@ dependencies {
     implementation(libs.ant)
 }
 
-def fatJar = tasks.register("fatJar", ShadowJar) {
+tasks.named('shadowJar', ShadowJar) {
     destinationDirectory.set(file("$rootDir/lib"))
     archiveFileName.set('proguard-ant.jar')
-    from sourceSets.main.output
-    configurations = [project.configurations.runtimeClasspath]
     manifest {
         attributes(
-                'Manifest-Version': '1.0',
                 'Multi-Release': true,
-                'Implementation-Version': archiveVersion.get())
+                'Implementation-Version': archiveVersion.get(),
+        )
     }
 }
 
-assemble.dependsOn fatJar
-
 afterEvaluate {
     publishing {
         publications.named(project.name) {
diff --git a/build.gradle b/build.gradle
index 36bee48e..feed765a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,6 +7,7 @@ plugins {
     id 'io.github.gradle-nexus.publish-plugin'
     id 'signing'
     alias(libs.plugins.kotlin.jvm) apply(false)
+    id "com.gradleup.shadow" version "9.1.0" apply false
 }
 
 allprojects {
@@ -170,7 +171,7 @@ distributions {
                             project(":retrace"),
                             project(":ant"),
                     ]
-                    from(distProjects.collect { it.tasks.named { it == "fatJar" } })
+                    from(distProjects.collect { it.tasks.named { it == "shadowJar" } })
                 }
                 into('docs') {
                     from('docs/md') {
diff --git a/gradle-plugin/build.gradle b/gradle-plugin/build.gradle
index a016efff..5fd3ae35 100644
--- a/gradle-plugin/build.gradle
+++ b/gradle-plugin/build.gradle
@@ -1,7 +1,7 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 plugins {
-    id 'com.github.johnrengelman.shadow'
+    id 'com.gradleup.shadow'
     id 'java-gradle-plugin'
     id 'org.jetbrains.kotlin.jvm'
     id 'maven-publish'
@@ -53,20 +53,20 @@ test {
 
 def localRepo = file("$buildDir/local-repo")
 
-def fatJar = tasks.register("fatJar", ShadowJar) {
+def shadowJar = tasks.named('shadowJar', ShadowJar) {
     destinationDirectory.set(localRepo)
     archiveFileName.set("proguard-gradle-${version}.jar")
-    from sourceSets.main.output
-    configurations = [project.configurations.fatJar]
+    configurations = provider { [project.configurations.fatJar] }
     manifest {
         attributes(
                 'Main-Class': 'proguard.ProGuard',
-                'Implementation-Version': archiveVersion.get())
+                'Implementation-Version': archiveVersion.get(),
+        )
     }
 }
 
 tasks.withType(Test).configureEach {
-    dependsOn fatJar
+    dependsOn shadowJar
     systemProperty "local.repo", localRepo.toURI()
     systemProperty "proguard.version", version
     systemProperty "agp.version", libs.versions.agp.get()
diff --git a/gui/build.gradle b/gui/build.gradle
index d795f857..76e3b5bd 100644
--- a/gui/build.gradle
+++ b/gui/build.gradle
@@ -1,7 +1,7 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 
 plugins {
-    id 'com.github.johnrengelman.shadow'
+    id 'com.gradleup.shadow'
     id 'java'
     id 'maven-publish'
 }
@@ -17,22 +17,18 @@ dependencies {
     implementation 'org.apache.logging.log4j:log4j-core:2.24.2'
 }
 
-def fatJar = tasks.register("fatJar", ShadowJar) {
+tasks.named('shadowJar', ShadowJar) {
     destinationDirectory.set(file("$rootDir/lib"))
     archiveFileName.set('proguardgui.jar')
-    from sourceSets.main.output
-    configurations = [project.configurations.runtimeClasspath]
     manifest {
         attributes(
-                'Manifest-Version': '1.0',
                 'Main-Class': 'proguard.gui.ProGuardGUI',
                 'Multi-Release': true,
-                'Implementation-Version': archiveVersion.get())
+                'Implementation-Version': archiveVersion.get(),
+        )
     }
 }
 
-assemble.dependsOn fatJar
-
 afterEvaluate {
     publishing {
         publications.named(project.name) {
diff --git a/proguard-app/build.gradle b/proguard-app/build.gradle
index 2b6ec799..3bd0b251 100644
--- a/proguard-app/build.gradle
+++ b/proguard-app/build.gradle
@@ -1,7 +1,7 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 
 plugins {
-    id 'com.github.johnrengelman.shadow'
+    id 'com.gradleup.shadow'
     id 'java'
     id 'application'
 }
@@ -10,23 +10,23 @@ repositories {
     mavenCentral()
 }
 
+application {
+    mainClass = 'proguard.ProGuard'
+}
+
 dependencies {
    implementation project(':base')
 }
 
 jar.manifest.attributes('Implementation-Version': version)
 
-def fatJar = tasks.register("fatJar",ShadowJar) {
-    mainClassName = 'proguard.ProGuard'
+tasks.named('shadowJar', ShadowJar) {
     destinationDirectory.set(file("$rootDir/lib"))
     archiveFileName.set('proguard.jar')
-    configurations = [project.configurations.runtimeClasspath]
     manifest {
         attributes(
                 'Main-Class': 'proguard.ProGuard',
                 'Multi-Release': true,
-                'Implementation-Version': archiveVersion.get())
+        )
     }
 }
-
-assemble.dependsOn fatJar
diff --git a/retrace/build.gradle b/retrace/build.gradle
index 52d26f94..14ae2595 100644
--- a/retrace/build.gradle
+++ b/retrace/build.gradle
@@ -1,7 +1,7 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 
 plugins {
-    id 'com.github.johnrengelman.shadow'
+    id 'com.gradleup.shadow'
     id 'java'
     id 'maven-publish'
 }
@@ -14,21 +14,17 @@ dependencies {
     implementation project(':base')
 }
 
-def fatJar = tasks.register("fatJar", ShadowJar) {
+tasks.named('shadowJar', ShadowJar) {
     destinationDirectory.set(file("$rootDir/lib"))
     archiveFileName.set('retrace.jar')
-    from sourceSets.main.output
-    configurations = [project.configurations.runtimeClasspath]
     manifest {
         attributes(
-                'Manifest-Version': '1.0',
                 'Multi-Release': true,
-                'Main-Class': 'proguard.retrace.ReTrace')
+                'Main-Class': 'proguard.retrace.ReTrace',
+        )
     }
 }
 
-assemble.dependsOn fatJar
-
 afterEvaluate {
     publishing {
         publications.named(project.name) {
diff --git a/settings.gradle b/settings.gradle
index a0337223..e3a34f96 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,9 +1,6 @@
 pluginManagement {
     resolutionStrategy {
         eachPlugin {
-            if (requested.id.id == 'com.github.johnrengelman.shadow') {
-                useVersion '8.1.1'
-            }
             if (requested.id.id == 'io.github.gradle-nexus.publish-plugin') {
                 useVersion '2.0.0'
             }