diff --git a/.gitignore b/.gitignore
index d1ac00fd4afb..581b1fdb0d9b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,5 @@
 !/temp/.gitkeep
 /example
 /vendor
+/build
 composer.lock
diff --git a/composer.json b/composer.json
index 545c2398f1d0..bc311d4b8df6 100644
--- a/composer.json
+++ b/composer.json
@@ -61,7 +61,18 @@
             "vendor/bin/ecs check bin packages src tests --fix",
             "bin/clean_levels.sh"
         ],
-        "phpstan": "vendor/bin/phpstan.phar analyse packages src tests --level max --configuration phpstan.neon"
+        "phpstan": "vendor/bin/phpstan.phar analyse packages src tests --level max --configuration phpstan.neon",
+        "prefix-rector": [
+            "rm -rf build/",
+            "php php-scoper.phar add-prefix --no-interaction --prefix='RectorPrefixed'",
+            "find build/ -type f -name '*.yml' | xargs perl -pi -e 's/((?:\\\\{1,2}\\w+|\\w+\\\\{1,2})(?:\\w+\\\\{0,2})+)/RectorPrefixed\\\\\\1/g'",
+            "find build/ -type f | xargs sed -i 's/RectorPrefixed\\\\Rector/Rector/g'",
+            "find build/ -type f | xargs sed -i 's/RectorPrefixed\\\\\\\\Rector/Rector/g'",
+            "find build/ -type f | xargs sed -i 's/use Symfony/use RectorPrefixed\\\\\\\\Symfony/g'",
+            "cp composer.json build/composer.json",
+            "cd build && composer dump-autoload",
+            "cd build && php bin/rector"
+        ]
     },
     "bin": [
         "bin/rector",
diff --git a/php-scoper.phar b/php-scoper.phar
new file mode 100644
index 000000000000..3db003ec20ed
Binary files /dev/null and b/php-scoper.phar differ
diff --git a/php-scoper.phar.pubkey b/php-scoper.phar.pubkey
new file mode 100644
index 000000000000..a1455c679358
--- /dev/null
+++ b/php-scoper.phar.pubkey
@@ -0,0 +1,14 @@
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----
diff --git a/scoper.inc.php b/scoper.inc.php
new file mode 100644
index 000000000000..f126496265b7
--- /dev/null
+++ b/scoper.inc.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+use Isolated\Symfony\Component\Finder\Finder;
+
+return [
+    'prefix' => 'RectorPrefixed',
+    'finders' => [
+        Finder::create()
+            ->files()
+            ->ignoreVCS(true)
+            ->notName('/LICENSE|.*\\.md|.*\\.dist|Makefile|composer\\.json|composer\\.lock/')
+            ->in('*')
+            ->exclude([
+                'docs',
+                'Tests'
+            ])
+        ,
+    ],
+    'patchers' => [
+        function (string $filePath, string $prefix, string $contents): string {
+            // Change the contents here.
+
+            return $contents;
+        },
+    ],
+];