diff --git a/src/main/java/io/devcon5/vertx/services/AbstractService.java b/src/main/java/io/devcon5/vertx/services/AbstractService.java
index 31f70f3..cc73fd3 100644
--- a/src/main/java/io/devcon5/vertx/services/AbstractService.java
+++ b/src/main/java/io/devcon5/vertx/services/AbstractService.java
@@ -124,6 +124,7 @@ public Future<Void> mount(final Router parent) {
      */
     protected void start(final Future<Void> startFuture) {
 
+        System.out.println("you shall not use system.out.println");
         start();
         startFuture.complete();
     }