diff --git a/RoboFile.php b/RoboFile.php
index 8df789b..a938b16 100644
--- a/RoboFile.php
+++ b/RoboFile.php
@@ -98,6 +98,11 @@ class RoboFile extends \Robo\Tasks {
         return defined("PHP_WINDOWS_VERSION_MAJOR");
     }
 
+    protected function blackhole(bool $all = false): string {
+        $hole = $this->isWindows() ? "nul" : "/dev/null";
+        return $all ? ">$hole 2>&1" : "2>$hole";
+    }
+
     protected function runTests(string $executor, string $set, array $args) : Result {
         switch ($set) {
             case "typical":
@@ -117,7 +122,7 @@ class RoboFile extends \Robo\Tasks {
         }
         $execpath = realpath(self::BASE."vendor-bin/phpunit/vendor/phpunit/phpunit/phpunit");
         $confpath = realpath(self::BASE_TEST."phpunit.xml");
-        $this->taskServer(8000)->host("localhost")->dir(self::BASE_TEST."docroot")->rawArg("-n")->arg(self::BASE_TEST."server.php")->background()->run();
+        $this->taskServer(8000)->host("localhost")->dir(self::BASE_TEST."docroot")->rawArg("-n")->arg(self::BASE_TEST."server.php")->rawArg($this->blackhole())->background()->run();
         return $this->taskExec($executor)->arg($execpath)->option("-c", $confpath)->args(array_merge($set, $args))->run();
     }