diff --git a/tests/Test/ServerTestHelper.php b/tests/Test/ServerTestHelper.php
index 6e10ca3..d1e75f3 100644
--- a/tests/Test/ServerTestHelper.php
+++ b/tests/Test/ServerTestHelper.php
@@ -134,6 +134,6 @@ public static function getNextPort(): int
      */
     private function getCommand(): string
     {
-        return \sprintf('/usr/bin/env php '.\escapeshellarg(__DIR__.'/server.php').' %d', $this->port);
+        return \sprintf('/usr/bin/env php %s %d', \escapeshellarg(__DIR__.'/server.php'), $this->port);
     }
 }