diff --git a/router-protobuf/build.gradle.kts b/router-protobuf/build.gradle.kts
index 6d422ccc..8c79fc55 100644
--- a/router-protobuf/build.gradle.kts
+++ b/router-protobuf/build.gradle.kts
@@ -1,21 +1,20 @@
-import com.google.protobuf.gradle.protobuf
-import com.google.protobuf.gradle.protoc
-
 plugins {
-    id("com.google.protobuf") version "0.8.19"
+    id("com.google.protobuf") version "0.9.4"
 }
 
 repositories {
     mavenCentral()
 }
 
+val protoVersion = "4.27.2"
+
 dependencies {
     implementation(kotlin("stdlib"))
     implementation(kotlin("reflect"))
 
     implementation("org.slf4j:slf4j-api:2.0.13")
-    api("com.google.protobuf:protobuf-java:3.25.3")
-    api("com.google.protobuf:protobuf-java-util:3.25.3")
+    api("com.google.protobuf:protobuf-java:$protoVersion")
+    api("com.google.protobuf:protobuf-java-util:$protoVersion")
     implementation("com.google.guava:guava:33.2.1-jre")
     api(project(":router"))
 
@@ -27,10 +26,10 @@ dependencies {
     testImplementation("com.jayway.jsonpath:json-path:2.9.0")
 }
 
-
 protobuf {
+    // Configure the protoc executable
     protoc {
-        // The artifact spec for the Protobuf Compiler
-        artifact = "com.google.protobuf:protoc:3.25.3"
+        // Download from repositories
+        artifact = "com.google.protobuf:protoc:$protoVersion"
     }
 }
\ No newline at end of file
diff --git a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoBufUtils.kt b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoBufUtils.kt
index e07ecf63..beafb8e6 100644
--- a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoBufUtils.kt
+++ b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoBufUtils.kt
@@ -4,12 +4,12 @@ import com.fasterxml.jackson.databind.JsonNode
 import com.fasterxml.jackson.databind.node.ArrayNode
 import com.fasterxml.jackson.databind.node.ObjectNode
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import com.google.protobuf.GeneratedMessageV3
+import com.google.protobuf.GeneratedMessage
 import com.google.protobuf.util.JsonFormat
 
 object ProtoBufUtils {
-    fun toJsonWithoutWrappers(proto: GeneratedMessageV3): String {
-        val message = JsonFormat.printer().omittingInsignificantWhitespace().includingDefaultValueFields().print(proto)
+    fun toJsonWithoutWrappers(proto: GeneratedMessage): String {
+        val message = JsonFormat.printer().omittingInsignificantWhitespace().alwaysPrintFieldsWithNoPresence().print(proto)
         return removeWrapperObjects(message)
     }
 
diff --git a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoDeserializationHandler.kt b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoDeserializationHandler.kt
index 36a163aa..40ff196a 100644
--- a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoDeserializationHandler.kt
+++ b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoDeserializationHandler.kt
@@ -19,7 +19,7 @@ class ProtoDeserializationHandler : DeserializationHandler {
         if (input.contentType() == null) {
             false
         } else {
-            MediaType.parse(input.contentType()).let { proto.isCompatibleWith(it) || protoStructuredSuffixWildcard.isCompatibleWith(it) }
+            MediaType.parse(input.contentType()!!).let { proto.isCompatibleWith(it) || protoStructuredSuffixWildcard.isCompatibleWith(it) }
         }
 
     override fun deserialize(
diff --git a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoSerializationHandler.kt b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoSerializationHandler.kt
index e6fd932c..4a041bd0 100644
--- a/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoSerializationHandler.kt
+++ b/router-protobuf/src/main/kotlin/io/moia/router/proto/ProtoSerializationHandler.kt
@@ -1,7 +1,7 @@
 package io.moia.router.proto
 
 import com.google.common.net.MediaType
-import com.google.protobuf.GeneratedMessageV3
+import com.google.protobuf.GeneratedMessage
 import io.moia.router.SerializationHandler
 import isCompatibleWith
 import java.util.Base64
@@ -13,13 +13,13 @@ class ProtoSerializationHandler : SerializationHandler {
     override fun supports(
         acceptHeader: MediaType,
         body: Any,
-    ): Boolean = body is GeneratedMessageV3
+    ): Boolean = body is GeneratedMessage
 
     override fun serialize(
         acceptHeader: MediaType,
         body: Any,
     ): String {
-        val message = body as GeneratedMessageV3
+        val message = body as GeneratedMessage
         return if (json.isCompatibleWith(acceptHeader) || jsonStructuredSuffixWildcard.isCompatibleWith(acceptHeader)) {
             ProtoBufUtils.toJsonWithoutWrappers(message)
         } else {
diff --git a/router-protobuf/src/test/proto/Sample.proto b/router-protobuf/src/test/proto/Sample.proto
index 95c164ba..7fb40b79 100644
--- a/router-protobuf/src/test/proto/Sample.proto
+++ b/router-protobuf/src/test/proto/Sample.proto
@@ -2,6 +2,10 @@ syntax = "proto3";
 
 package io.moia.router.proto.sample;
 
+option java_multiple_files = false;
+option java_outer_classname = "SampleOuterClass";
+option java_package = "io.moia.router.proto.sample";
+
 import "google/protobuf/wrappers.proto";
 
 message Sample {