diff --git a/src/mqtt.service.ts b/src/mqtt.service.ts
index c8065cb..a252432 100644
--- a/src/mqtt.service.ts
+++ b/src/mqtt.service.ts
@@ -1,5 +1,5 @@
 import { EventEmitter, Inject, Injectable } from '@angular/core';
-import { ISubscriptionGrant } from './mqtt-types';
+import { ISubscriptionGrant, IClientSubscribeOptions } from './mqtt-types';
 import { connect } from '../vendor/mqtt.browserified.js';
 import * as extend from 'xtend';
 
@@ -142,8 +142,8 @@ export class MqttService {
    * The last one unsubscribing this filter executes a mqtt unsubscribe.
    * Every new subscriber gets the latest message.
    */
-  public observeRetained(filterString: string): Observable<IMqttMessage> {
-    return this._generalObserve(filterString, () => publishReplay(1));
+  public observeRetained(filterString: string, opts: IClientSubscribeOptions = { qos: 1 }): Observable<IMqttMessage> {
+    return this._generalObserve(filterString, () => publishReplay(1), opts);
   }
 
   /**
@@ -152,8 +152,8 @@ export class MqttService {
    * The first one subscribing to the resulting observable executes a mqtt subscribe.
    * The last one unsubscribing this filter executes a mqtt unsubscribe.
    */
-  public observe(filterString: string): Observable<IMqttMessage> {
-    return this._generalObserve(filterString, () => publish());
+  public observe(filterString: string, opts: IClientSubscribeOptions = { qos: 1 }): Observable<IMqttMessage> {
+    return this._generalObserve(filterString, () => publish(), opts);
   }
 
   /**
@@ -164,7 +164,7 @@ export class MqttService {
    * Depending on the publish function, the messages will either be replayed after new
    * subscribers subscribe or the messages are just passed through
    */
-  private _generalObserve(filterString: string, publishFn: Function): Observable<IMqttMessage> {
+  private _generalObserve(filterString: string, publishFn: Function, opts: IClientSubscribeOptions): Observable<IMqttMessage> {
     if (!this.client) {
       throw new Error('mqtt client not connected');
     }
@@ -175,7 +175,7 @@ export class MqttService {
         // refcount is decreased on unsubscribe.
         () => {
           const subscription: Subscription = new Subscription();
-          this.client.subscribe(filterString, (err, granted: ISubscriptionGrant[]) => {
+          this.client.subscribe(filterString, opts, (err, granted: ISubscriptionGrant[]) => {
             if (granted) { // granted can be undefined when an error occurs when the client is disconnecting
               granted.forEach((granted_: ISubscriptionGrant) => {
                 if (granted_.qos === 128) {