diff --git a/devtoolslib/android_shell.py b/devtoolslib/android_shell.py
index ca7d5c1..daa2443 100644
--- a/devtoolslib/android_shell.py
+++ b/devtoolslib/android_shell.py
@@ -395,6 +395,7 @@
           host_port = self._forward_host_port_to_device(0, device_port)
           print ('Dart observatory available at the host at http://127.0.0.1:%d'
                  % host_port)
+          sys.stdout.flush()
 
     logcat_watch_thread = threading.Thread(
         target=_forward_observatories_as_needed)