diff --git a/packages/fastboot-app-server/src/fastboot-app-server.js b/packages/fastboot-app-server/src/fastboot-app-server.js
index aff9a57c..a3efb570 100644
--- a/packages/fastboot-app-server/src/fastboot-app-server.js
+++ b/packages/fastboot-app-server/src/fastboot-app-server.js
@@ -63,7 +63,7 @@ class FastBootAppServer {
     }
   }
 
-  start() {
+  start(callback) {
     if (cluster.isWorker) { return; }
 
     return this.initializeApp()
@@ -74,6 +74,11 @@ class FastBootAppServer {
           this.broadcast({ event: 'error', error: this.initializationError.stack });
         }
       })
+      .then(() => {
+        if (typeof callback === "function") {
+          callback();
+        }
+      })
       .catch(err => {
         this.ui.writeLine(err.stack);
       });