diff --git a/src/Console/InstallCommand.php b/src/Console/InstallCommand.php
index e7f711bdd..70ac82ee6 100644
--- a/src/Console/InstallCommand.php
+++ b/src/Console/InstallCommand.php
@@ -106,8 +106,10 @@ public function handle()
         // Tests...
         $stubs = $this->getTestStubsPath();
 
-        if ($this->option('pest')) {
-            $this->removeComposerDevPackages(['phpunit/phpunit']);
+        if ($this->option('pest') || $this->isUsingPest()) {
+            if ($this->hasComposerPackage('phpunit/phpunit')) {
+                $this->removeComposerDevPackages(['phpunit/phpunit']);
+            }
 
             if (! $this->requireComposerDevPackages(['pestphp/pest:^2.0', 'pestphp/pest-plugin-laravel:^2.0'])) {
                 return 1;
@@ -649,11 +651,25 @@ protected function installMiddlewareAfter($after, $name, $group = 'web')
      */
     protected function getTestStubsPath()
     {
-        return $this->option('pest')
+        return $this->option('pest') || $this->isUsingPest()
             ? __DIR__.'/../../stubs/pest-tests'
             : __DIR__.'/../../stubs/tests';
     }
 
+    /**
+     * Determine if the given Composer package is installed.
+     *
+     * @param  string  $package
+     * @return bool
+     */
+    protected function hasComposerPackage($package)
+    {
+        $packages = json_decode(file_get_contents(base_path('composer.json')), true);
+
+        return array_key_exists($package, $packages['require'] ?? [])
+            || array_key_exists($package, $packages['require-dev'] ?? []);
+    }
+
     /**
      * Installs the given Composer Packages into the application.
      *
@@ -880,6 +896,17 @@ protected function afterPromptingForMissingArguments(InputInterface $input, Outp
         $input->setOption('pest', select(
             label: 'Which testing framework do you prefer?',
             options: ['PHPUnit', 'Pest'],
+            default: $this->isUsingPest() ? 'Pest' : 'PHPUnit',
         ) === 'Pest');
     }
+
+    /**
+     * Determine whether the project is already using Pest.
+     *
+     * @return bool
+     */
+    protected function isUsingPest()
+    {
+        return class_exists(\Pest\TestSuite::class);
+    }
 }