diff --git a/cli/Valet/Upgrader.php b/cli/Valet/Upgrader.php
new file mode 100644
index 000000000..f59d6ae5d
--- /dev/null
+++ b/cli/Valet/Upgrader.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Valet;
+
+use Configuration;
+use Site;
+
+class Upgrader
+{
+    public function __construct(public Filesystem $files)
+    {
+    }
+
+    /**
+     * Relocate config dir to ~/.config/valet/ if found in old location.
+     *
+     * @return void
+     */
+    public function relocateOldConfig()
+    {
+        if (is_dir(VALET_LEGACY_HOME_PATH) && ! is_dir(VALET_HOME_PATH)) {
+            Configuration::createConfigurationDirectory();
+        }
+    }
+
+    public function pruneMissingDirectories()
+    {
+        Configuration::prune();
+    }
+
+    public function pruneSymbolicLinks()
+    {
+        Site::pruneLinks();
+    }
+
+    public function fixOldSampleValetDriver()
+    {
+        $samplePath = VALET_HOME_PATH.'/Drivers/SampleValetDriver.php';
+
+        if ($this->files->exists($samplePath)) {
+            if (! str_contains($this->files->get($samplePath), 'namespace')) {
+                $this->files->putAsUser(
+                    VALET_HOME_PATH.'/Drivers/SampleValetDriver.php',
+                    $this->files->getStub('SampleValetDriver.php')
+                );
+            }
+        }
+    }
+
+    public function errorIfOldCustomDrivers()
+    {
+        $driversPath = VALET_HOME_PATH.'/Drivers';
+
+        foreach ($this->files->scanDir($driversPath) as $driver) {
+            if (! str_contains($this->files->get($driversPath.'/'.$driver), 'namespace')) {
+                warning('Please make sure all custom drivers have been upgraded for Valet 4.');
+                exit;
+            }
+        }
+    }
+}
diff --git a/cli/app.php b/cli/app.php
index eb2ccadca..30c750202 100644
--- a/cli/app.php
+++ b/cli/app.php
@@ -9,12 +9,15 @@
 use Symfony\Component\Console\Question\ConfirmationQuestion;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Valet\Drivers\ValetDriver;
+
 use function Valet\info;
 use function Valet\output;
 use function Valet\table;
 use function Valet\warning;
 use function Valet\writer;
 
+$version = '4.0.0';
+
 /**
  * Load correct autoloader depending on install location.
  */
@@ -26,24 +29,14 @@
     require_once getenv('HOME').'/.composer/vendor/autoload.php';
 }
 
-/**
- * Relocate config dir to ~/.config/valet/ if found in old location.
- */
-if (is_dir(VALET_LEGACY_HOME_PATH) && ! is_dir(VALET_HOME_PATH)) {
-    Configuration::createConfigurationDirectory();
-}
-
 /**
  * Create the application.
  */
 Container::setInstance(new Container);
 
-$version = '4.0.0';
-
 $app = new Application('Laravel Valet', $version);
 
-$dispatcher = new EventDispatcher();
-$app->setDispatcher($dispatcher);
+$app->setDispatcher($dispatcher = new EventDispatcher());
 
 $dispatcher->addListener(
     ConsoleEvents::COMMAND,
@@ -51,14 +44,11 @@ function (ConsoleCommandEvent $event) {
         writer($event->getOutput());
     });
 
-/**
- * Prune missing directories and symbolic links on every command.
- */
-if (is_dir(VALET_HOME_PATH)) {
-    Configuration::prune();
-
-    Site::pruneLinks();
-}
+Upgrader::relocateOldConfig();
+Upgrader::pruneMissingDirectories();
+Upgrader::pruneSymbolicLinks();
+Upgrader::fixOldSampleValetDriver();
+Upgrader::errorIfOldCustomDrivers();
 
 /**
  * Install Valet and any required services.
diff --git a/cli/includes/facades.php b/cli/includes/facades.php
index 2559c0395..96be663fa 100644
--- a/cli/includes/facades.php
+++ b/cli/includes/facades.php
@@ -59,6 +59,9 @@ class PhpFpm extends Facade
 class Site extends Facade
 {
 }
+class Upgrader extends Facade
+{
+}
 class Valet extends Facade
 {
 }
diff --git a/cli/stubs/SampleValetDriver.php b/cli/stubs/SampleValetDriver.php
index b392636de..119816027 100644
--- a/cli/stubs/SampleValetDriver.php
+++ b/cli/stubs/SampleValetDriver.php
@@ -1,5 +1,9 @@
 <?php
 
+namespace Valet\Drivers\Specific;
+
+use Valet\Drivers\ValetDriver;
+
 class SampleValetDriver extends ValetDriver
 {
     /**