diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index c51b6b417..2d7abb832 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -10,6 +10,7 @@
     <php>
         <ini name="error_reporting" value="-1" />
         <env name="TEST_DATABASE_DSN" value="mysql://root:@127.0.0.1:3306/test_maker" />
+        <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak_vendors" />
     </php>
 
     <testsuites>
diff --git a/src/Test/MakerTestEnvironment.php b/src/Test/MakerTestEnvironment.php
index bd85696c6..40d05c6ae 100644
--- a/src/Test/MakerTestEnvironment.php
+++ b/src/Test/MakerTestEnvironment.php
@@ -56,9 +56,9 @@ private function __construct(MakerTestDetails $testDetails)
         $this->cachePath = realpath($cachePath);
         $this->flexPath = $this->cachePath.'/flex_project';
 
-        $this->path = $this->cachePath.DIRECTORY_SEPARATOR.$testDetails->getUniqueCacheDirectoryName();
+        $this->path = $this->cachePath.\DIRECTORY_SEPARATOR.$testDetails->getUniqueCacheDirectoryName();
 
-        $this->snapshotFile = $this->path.DIRECTORY_SEPARATOR.basename($this->path).'.json';
+        $this->snapshotFile = $this->path.\DIRECTORY_SEPARATOR.basename($this->path).'.json';
     }
 
     public static function create(MakerTestDetails $testDetails): self
@@ -301,6 +301,16 @@ private function buildFlexSkeleton()
         MakerTestProcess::create('composer require phpunit browser-kit symfony/css-selector', $this->flexPath)
                         ->run();
 
+        $replacements = [
+            [
+                'filename' => 'phpunit.xml.dist',
+                'find' => '</php>',
+                'replace' => '    <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak_vendors" />'."\n".'    </php>',
+            ],
+        ];
+
+        $this->processReplacements($replacements, $this->flexPath);
+
         MakerTestProcess::create('php bin/console cache:clear --no-warmup', $this->flexPath)
                         ->run();
     }