diff --git a/protoc-gen/src/main/scala/protocgen/CodeGenResponse.scala b/protoc-gen/src/main/scala/protocgen/CodeGenResponse.scala
index 3d38fa1..31d536a 100644
--- a/protoc-gen/src/main/scala/protocgen/CodeGenResponse.scala
+++ b/protoc-gen/src/main/scala/protocgen/CodeGenResponse.scala
@@ -1,15 +1,40 @@
 package protocgen
 
+import com.google.protobuf.UnknownFieldSet
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse
 import scala.collection.JavaConverters._
 
 sealed trait CodeGenResponse {
   def toCodeGeneratorResponse: CodeGeneratorResponse =
     this match {
-      case CodeGenResponse.Internal.Success(files, features) =>
+      case value: CodeGenResponse.Internal.Success =>
         val b = CodeGeneratorResponse.newBuilder()
-        b.addAllFile(files.asJava)
-        b.setSupportedFeatures(features.map(_.getNumber()).sum)
+        b.addAllFile(value.files.asJava)
+        b.setSupportedFeatures(value.supportedFeatures.map(_.getNumber()).sum)
+        b.setUnknownFields(
+          // https://github.com/protocolbuffers/protobuf/blob/1f60d67437d7f57700/src/google/protobuf/compiler/plugin.proto#L105-L115
+          UnknownFieldSet
+            .newBuilder()
+            .addField(
+              3,
+              UnknownFieldSet.Field
+                .newBuilder()
+                .addVarint(
+                  value.minimumEdition
+                )
+                .build()
+            )
+            .addField(
+              4,
+              UnknownFieldSet.Field
+                .newBuilder()
+                .addVarint(
+                  value.maximumEdition
+                )
+                .build()
+            )
+            .build()
+        )
         b.build()
       case CodeGenResponse.Internal.Failure(msg) =>
         val b = CodeGeneratorResponse.newBuilder()
@@ -20,13 +45,21 @@ sealed trait CodeGenResponse {
 
 object CodeGenResponse {
   def succeed(files: Seq[CodeGeneratorResponse.File]): CodeGenResponse =
-    Internal.Success(files, Set())
+    Internal.Success(files, Set(), 0, 0)
 
   def succeed(
       files: Seq[CodeGeneratorResponse.File],
       supportedFeatures: Set[CodeGeneratorResponse.Feature]
   ): CodeGenResponse =
-    Internal.Success(files, supportedFeatures)
+    Internal.Success(files, supportedFeatures, 0, 0)
+
+  def succeed(
+      files: Seq[CodeGeneratorResponse.File],
+      supportedFeatures: Set[CodeGeneratorResponse.Feature],
+      minimumEdition: Int,
+      maximumEdition: Int
+  ): CodeGenResponse =
+    Internal.Success(files, supportedFeatures, minimumEdition, maximumEdition)
 
   def fail(message: String): CodeGenResponse = Internal.Failure(message)
 
@@ -34,8 +67,10 @@ object CodeGenResponse {
     final case class Failure(val message: String) extends CodeGenResponse
 
     final case class Success(
-        val files: Seq[CodeGeneratorResponse.File],
-        supportedFeatures: Set[CodeGeneratorResponse.Feature]
+        files: Seq[CodeGeneratorResponse.File],
+        supportedFeatures: Set[CodeGeneratorResponse.Feature],
+        minimumEdition: Int,
+        maximumEdition: Int
     ) extends CodeGenResponse
   }
 }