diff --git a/lib/behat/classes/util.php b/lib/behat/classes/util.php
index 80f59232581..17dbae8ae22 100644
--- a/lib/behat/classes/util.php
+++ b/lib/behat/classes/util.php
@@ -173,6 +173,7 @@ class behat_util extends testing_util {
                 }
             }
             echo $output;
+            ob_flush();
         }
     }