diff --git a/package.json b/package.json
index a86accd..bbc5124 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
    "name": "nodename-core",
-   "version": "0.3.1",
+   "version": "0.3.2",
    "main": "lib/index.js",
    "types": "lib/index.d.ts",
    "author": "Fabian Stamm <dev@fabianstamm.de>",
diff --git a/src/core.ts b/src/core.ts
index dfb48cf..afa103a 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -31,6 +31,10 @@ export interface Plugin {
    init(core: DnsCore): Promise<void>
 }
 
+export type ListenerCallback =
+   ((data: Buffer, sender: string, max_size?: number) => Promise<Buffer>) |
+   ((data: Buffer, sender: string, answer: Writable) => Promise<void>)
+
 export interface ListenerPlugin extends Plugin {
    /**
     * This method is for registering a callback that is called
@@ -38,8 +42,7 @@ export interface ListenerPlugin extends Plugin {
     * The function returns the Answer data. Errors shouldn't be possible
     * by this function
     */
-   registerCallback(callback: (data: Buffer, sender: string, max_size?: number) => Promise<Buffer>): void
-   registerCallback(callback: (data: Buffer, sender: string, answer: Writable) => Promise<void>)
+   registerCallback(callback: ListenerCallback): void
 }
 
 export class ListenerManager {
@@ -53,7 +56,7 @@ export class ListenerManager {
       return Promise.all(this._listener.map(e => e.init(core)))
    }
 
-   registerCallback(callback: (data: Buffer, sender: string, max_size?: number) => Promise<Buffer>) {
+   registerCallback(callback: ListenerCallback) {
       this._listener.forEach(e => e.registerCallback(callback))
    }
 }
@@ -282,7 +285,13 @@ export class DnsCore {
       this.listenerManager.registerCallback(this.onMessage.bind(this));
    }
 
-   private async onMessage(data: Buffer, sender: string, max_size: number = 0) {
+   private onMessage: ListenerCallback = async (data: Buffer, sender: string, r) => {
+      let max_size = 128 * 1024;
+      let stream = true;
+      if (typeof r === "number") {
+         max_size = r;
+         stream = false;
+      }
       let request = new Request(data, sender, max_size);
       let questionqueue: Promise<void>[] = [];
       let handleQuestion = question => {
@@ -304,6 +313,11 @@ export class DnsCore {
       }
       request.questions.map(q => handleQuestion(q));
       await Promise.all(questionqueue);
-      return request.serialize();
+      let res = request.serialize();
+      if (stream) {
+         (<Writable>r).write(res);
+      } else {
+         return r;
+      }
    }
 }
\ No newline at end of file