diff --git a/composer/Plugin/Scaffold/ManageGitIgnore.php b/composer/Plugin/Scaffold/ManageGitIgnore.php
index 17e63e07a41e1cd3ade3847280d4399d1fe93029..5f1bb9dc9574a69cd802589eda6adae1f2e49af0 100644
--- a/composer/Plugin/Scaffold/ManageGitIgnore.php
+++ b/composer/Plugin/Scaffold/ManageGitIgnore.php
@@ -91,9 +91,8 @@ protected function managementOfGitIgnoreEnabled(ScaffoldOptions $options) {
     }
 
     // If the composer.json did not specify whether or not .gitignore files
-    // should be managed, then manage them if the vendor directory is not
-    // committed.
-    return !Git::checkTracked($this->io, 'vendor', $this->dir);
+    // should be managed, then manage them if the vendor directory is ignored.
+    return Git::checkIgnore($this->io, 'vendor', $this->dir);
   }
 
   /**
diff --git a/composer/Plugin/Scaffold/README.md b/composer/Plugin/Scaffold/README.md
index 5b7ce24d8a22fb46d6d7a5ea5840d247916647c3..c4a060627237b7c1a0a1c5bce482c072fc9c4327 100644
--- a/composer/Plugin/Scaffold/README.md
+++ b/composer/Plugin/Scaffold/README.md
@@ -302,7 +302,7 @@ manage `.gitignore` files for files written during the scaffold operation.
 - true: `.gitignore` files will be updated when scaffold files are written.
 - false: `.gitignore` files will never be modified.
 - Not set: `.gitignore` files will be updated if the target directory is a local
-working copy of a git repository, and the `vendor` directory is not committed
+working copy of a git repository, and the `vendor` directory is ignored
 in that repository.
 
 ### locations