diff --git a/Dockerfile b/Dockerfile
index adb7530..d2de64c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,5 @@
-FROM gcr.io/distroless/java17-debian11
-COPY build/libs/tms-event-api-all.jar app/app.jar
-ENV PORT=8080
-EXPOSE $PORT
-WORKDIR app
-CMD ["app.jar"]
+FROM ghcr.io/navikt/baseimages/temurin:21
+
+ENV JAVA_OPTS='-XX:MaxRAMPercentage=75'
+
+COPY build/libs/*.jar ./
diff --git a/build.gradle.kts b/build.gradle.kts
index d3e6e0e..ac5c738 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,18 +1,17 @@
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
 
 plugins {
-    // Apply the Kotlin JVM plugin to add support for Kotlin on the JVM.
     kotlin("jvm").version(Kotlin.version)
     kotlin("plugin.serialization").version(Kotlin.version)
 
-    id(Shadow.pluginId) version (Shadow.version)
-    // Apply the application plugin to add support for building a CLI application.
+    id(TmsJarBundling.plugin)
+
     application
 }
 
 kotlin {
     jvmToolchain {
-        languageVersion.set(JavaLanguageVersion.of(17))
+        languageVersion.set(JavaLanguageVersion.of(21))
     }
 }
 
@@ -52,8 +51,6 @@ dependencies {
     testImplementation(Kluent.kluent)
     testImplementation(Mockk.mockk)
     testImplementation(Junit.params)
-    testImplementation("io.ktor:ktor-server-test-host-jvm:2.3.5")
-    testImplementation("org.jetbrains.kotlin:kotlin-test-junit:1.9.10")
     testImplementation(TmsTestUtils.testUtils)
 
     testRuntimeOnly(Jjwt.impl)
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index cbcc24a..3999176 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -1,5 +1,6 @@
 plugins {
     `kotlin-dsl`
+    `maven-publish`
 }
 
 repositories {
@@ -8,6 +9,21 @@ repositories {
 
 kotlin {
     jvmToolchain {
-        languageVersion.set(JavaLanguageVersion.of(17))
+        languageVersion.set(JavaLanguageVersion.of(21))
+    }
+}
+
+gradlePlugin {
+    plugins {
+        create("jar-bundling") {
+            id = "no.nav.tms.jar-bundling"
+            implementationClass = "JarBundling"
+        }
+    }
+}
+
+publishing {
+    repositories {
+        mavenLocal()
     }
 }
diff --git a/buildSrc/src/main/kotlin/jarBundling.kt b/buildSrc/src/main/kotlin/jarBundling.kt
new file mode 100644
index 0000000..0dc80e1
--- /dev/null
+++ b/buildSrc/src/main/kotlin/jarBundling.kt
@@ -0,0 +1,72 @@
+import org.gradle.api.DefaultTask
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.plugins.JavaApplication
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.TaskAction
+import org.gradle.jvm.tasks.Jar
+import java.io.File
+
+// Managed by tms-dependency-admin.
+
+abstract class JarBundling : Plugin<Project> {
+
+    override fun apply(target: Project) {
+
+        val configureTask = target.tasks.register("configureJar", ConfigureJarTask::class.java) {
+            this.application = target
+
+            val classes = target.tasks.named("classes")
+
+            dependsOn(classes)
+        }
+
+        val packageTask = target.tasks.register("packageJar", BundleJarsTask::class.java) {
+            this.application = target
+        }
+
+        target.tasks.withType(Jar::class.java) {
+            dependsOn(configureTask)
+            finalizedBy(packageTask)
+        }
+    }
+}
+
+abstract class ConfigureJarTask : DefaultTask() {
+    @Input
+    lateinit var application: Project
+
+    @TaskAction
+    fun action() {
+        application.tasks.withType(Jar::class.java) {
+
+            val javaApplication = application.extensions.getByType(JavaApplication::class.java)
+
+            val mainClassName = javaApplication.mainClass
+
+            archiveBaseName.set("app")
+            manifest {
+                val classpath = application.configurations.getByName("runtimeClasspath")
+                attributes["Main-Class"] = mainClassName
+                attributes["Class-Path"] = classpath.joinToString(separator = " ") {
+                    it.name
+                }
+            }
+        }
+    }
+}
+
+abstract class BundleJarsTask : DefaultTask() {
+    @Input
+    lateinit var application: Project
+
+    @TaskAction
+    fun action() {
+        val classpath = application.configurations.getByName("runtimeClasspath")
+
+        classpath.forEach {
+            val file = File("${application.layout.buildDirectory.get()}/libs/${it.name}")
+            if (!file.exists()) it.copyTo(file)
+        }
+    }
+}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index b82aa23..cea7a79 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/src/main/kotlin/no/nav/tms/event/api/App.kt b/src/main/kotlin/no/nav/tms/event/api/App.kt
index 9a91a16..46cb84a 100644
--- a/src/main/kotlin/no/nav/tms/event/api/App.kt
+++ b/src/main/kotlin/no/nav/tms/event/api/App.kt
@@ -111,7 +111,7 @@ fun Application.api(
 }
 
 private fun Application.configureShutdownHook(httpClient: HttpClient) {
-    environment.monitor.subscribe(ApplicationStopping) {
+    monitor.subscribe(ApplicationStopping) {
         httpClient.close()
     }
 }
diff --git a/src/main/kotlin/no/nav/tms/event/api/varsel/VarselReader.kt b/src/main/kotlin/no/nav/tms/event/api/varsel/VarselReader.kt
index 5cb7575..502b5ae 100644
--- a/src/main/kotlin/no/nav/tms/event/api/varsel/VarselReader.kt
+++ b/src/main/kotlin/no/nav/tms/event/api/varsel/VarselReader.kt
@@ -10,6 +10,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import no.nav.tms.event.api.config.AzureTokenFetcher
 import no.nav.tms.token.support.azure.validation.AzureHeader
+import java.net.URI
 import java.net.URL
 
 class VarselReader(
@@ -21,7 +22,7 @@ class VarselReader(
         fnr: String,
         varselPath: String,
     ): List<DetaljertVarsel> {
-        val completePathToEndpoint = URL("$varselAuthorityUrl/$varselPath")
+        val completePathToEndpoint = URI.create("$varselAuthorityUrl/$varselPath").toURL()
         val azureToken = azureTokenFetcher.fetchTokenForVarselAuthority()
         return client.getWithAzureAndFnr(completePathToEndpoint, azureToken, fnr)
     }