diff --git a/src/SiteAlias/ProcessManager.php b/src/SiteAlias/ProcessManager.php
index 0b90d09f2a..4884111720 100644
--- a/src/SiteAlias/ProcessManager.php
+++ b/src/SiteAlias/ProcessManager.php
@@ -68,7 +68,7 @@ public function drushScript(SiteAliasInterface $siteAlias)
         // If the target is a local Drupal site that has a vendor/bin/drush,
         // then use that.
         if ($siteAlias->hasRoot()) {
-            $localDrushScript = Path::join($siteAlias->root(), 'vendor/bin/drush');
+            $localDrushScript = Path::join($siteAlias->root(), '../vendor/bin/drush');
             if (file_exists($localDrushScript)) {
                 return $localDrushScript;
             }