diff --git a/core/tests/Drupal/BuildTests/Composer/ComposerValidateTest.php b/core/tests/Drupal/BuildTests/Composer/ComposerValidateTest.php
index 39bab190acfd4ff08665cb0b092a3fecdb443f4e..fa8699db824575659e484d3736a58245dd53c506 100644
--- a/core/tests/Drupal/BuildTests/Composer/ComposerValidateTest.php
+++ b/core/tests/Drupal/BuildTests/Composer/ComposerValidateTest.php
@@ -25,7 +25,7 @@ public function provideComposerJson() {
    * @dataProvider provideComposerJson
    */
   public function testValidateComposer($path) {
-    $this->executeCommand('./vendor/bin/composer validate --strict --no-check-all ' . $path);
+    $this->executeCommand('vendor/bin/composer validate --strict --no-check-all ' . $path);
     $this->assertCommandSuccessful();
   }
 
diff --git a/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
index 92c4a21d109c81907fe6ab7c311b766f267d1332..26753bc7bfdedfc678daa63938601086a01d4189 100644
--- a/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
+++ b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
@@ -178,7 +178,7 @@ public function testTemplateCreateProject($project, $package_dir, $docroot_dir)
     // It is necessary to do this globally rather than in our SUT composer.json
     // in order to ensure that Packagist is disabled during the
     // `composer create-project` command.
-    $this->executeCommand("COMPOSER_HOME=$composer_home ./vendor/bin/composer config --no-interaction --global repo.packagist false");
+    $this->executeCommand("COMPOSER_HOME=$composer_home vendor/bin/composer config --no-interaction --global repo.packagist false");
     $this->assertCommandSuccessful();
 
     // Create a "Composer"-type repository containing one entry for every
diff --git a/core/tests/Drupal/BuildTests/Framework/Tests/HtRouterTest.php b/core/tests/Drupal/BuildTests/Framework/Tests/HtRouterTest.php
index 096a7138abb4eb65bb5b9a13707fd15167f050a4..57c93a0d42703614d39cafe1f1d1c0a7a07bcdcd 100644
--- a/core/tests/Drupal/BuildTests/Framework/Tests/HtRouterTest.php
+++ b/core/tests/Drupal/BuildTests/Framework/Tests/HtRouterTest.php
@@ -22,7 +22,7 @@ public function testHtRouter() {
     }
 
     $this->copyCodebase();
-    $this->executeCommand('COMPOSER_DISCARD_CHANGES=true ./vendor/bin/composer install --no-dev --no-interaction');
+    $this->executeCommand('COMPOSER_DISCARD_CHANGES=true vendor/bin/composer install --no-dev --no-interaction');
     $this->assertErrorOutputContains('Generating autoload files');
     $this->installQuickStart('minimal');
     $this->formLogin($this->adminUsername, $this->adminPassword);
diff --git a/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Functional/ComposerHookTest.php b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Functional/ComposerHookTest.php
index 4a8f86659758f8e7c04e37138e7062747d9740e6..aec9575d9a909148d544ddf41771c771417569f4 100644
--- a/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Functional/ComposerHookTest.php
+++ b/core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Functional/ComposerHookTest.php
@@ -115,7 +115,7 @@ public function testComposerHooks() {
     $sut = $this->fixturesDir . '/create-project-test';
     $filesystem = new Filesystem();
     $filesystem->remove($sut);
-    $stdout = $this->mustExec("./vendor/bin/composer create-project --repository=packages.json fixtures/drupal-drupal {$sut}", $this->fixturesDir, ['COMPOSER_MIRROR_PATH_REPOS' => 1]);
+    $stdout = $this->mustExec("vendor/bin/composer create-project --repository=packages.json fixtures/drupal-drupal {$sut}", $this->fixturesDir, ['COMPOSER_MIRROR_PATH_REPOS' => 1]);
     $this->assertDirectoryExists($sut);
     $this->assertStringContainsString('Scaffolding files for fixtures/drupal-drupal', $stdout);
     $this->assertScaffoldedFile($sut . '/index.php', FALSE, 'Test version of index.php from drupal/core');