diff --git a/src/Configuration/RectorConfigBuilder.php b/src/Configuration/RectorConfigBuilder.php
index 8569aef678f..97411cb1c03 100644
--- a/src/Configuration/RectorConfigBuilder.php
+++ b/src/Configuration/RectorConfigBuilder.php
@@ -62,6 +62,17 @@ final class RectorConfigBuilder
         'withCodingStyleLevel' => [SetList::CODING_STYLE, 'coding style'],
     ];
 
+    /**
+     * The composer-based set of the extensions that rector-src does not require, so their set list class cannot be
+     * imported here. Resolved at run-time; an extension that ships no such set falls back to its set group.
+     *
+     * @var array<SetGroup::*, string>
+     */
+    private const array EXTENSION_COMPOSER_BASED_SET_LISTS = [
+        SetGroup::LARAVEL => 'RectorLaravel\\Set\\LaravelSetList::COMPOSER_BASED',
+        SetGroup::DRUPAL => 'DrupalRector\\Set\\DrupalSetList::COMPOSER_BASED',
+    ];
+
     /**
      * @var string[]
      */
@@ -741,10 +752,24 @@ public function withComposerBased(
             SetGroup::DRUPAL => $drupal,
         ];
 
-        foreach ($setMap as $setPath => $isEnabled) {
-            if ($isEnabled) {
-                $this->setGroups[] = $setPath;
+        foreach ($setMap as $setGroup => $isEnabled) {
+            if (! $isEnabled) {
+                continue;
+            }
+
+            $setListConstant = self::EXTENSION_COMPOSER_BASED_SET_LISTS[$setGroup];
+            if (defined($setListConstant)) {
+                $setFilePath = constant($setListConstant);
+                Assert::string($setFilePath);
+
+                // single set, as every rule inside is bound to the installed package version on its own
+                $this->sets[] = $setFilePath;
+                continue;
             }
+
+            // @deprecated fallback for extensions that still describe their sets as objects,
+            // instead of bonding the rules themselves
+            $this->setGroups[] = $setGroup;
         }
 
         if ($phpunit) {
diff --git a/tests/Configuration/ExtensionComposerBasedSetTest.php b/tests/Configuration/ExtensionComposerBasedSetTest.php
new file mode 100644
index 00000000000..de5873a81cc
--- /dev/null
+++ b/tests/Configuration/ExtensionComposerBasedSetTest.php
@@ -0,0 +1,73 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Configuration;
+
+use PHPUnit\Framework\TestCase;
+use Rector\Configuration\RectorConfigBuilder;
+use Rector\Set\Enum\SetGroup;
+use ReflectionClass;
+
+final class ExtensionComposerBasedSetTest extends TestCase
+{
+    /**
+     * Both toggles of withComposerBased() that point at an extension package must have a set list mapped,
+     * otherwise the lookup hits an undefined array key.
+     */
+    public function testEverySetGroupToggleHasASetListMapped(): void
+    {
+        $extensionSetLists = $this->provideExtensionComposerBasedSetLists();
+
+        self::assertArrayHasKey(SetGroup::LARAVEL, $extensionSetLists);
+        self::assertArrayHasKey(SetGroup::DRUPAL, $extensionSetLists);
+
+        foreach ($extensionSetLists as $setListConstant) {
+            self::assertMatchesRegularExpression('#^\w+(\\\\\w+)+::\w+$#', $setListConstant);
+        }
+    }
+
+    /**
+     * The extension packages are not required by rector-src, so their constant is undefined here and the
+     * deprecated set group has to keep working.
+     */
+    public function testFallsBackToTheSetGroupWhenTheExtensionIsNotInstalled(): void
+    {
+        foreach ($this->provideExtensionComposerBasedSetLists() as $setListConstant) {
+            self::assertFalse(defined($setListConstant), $setListConstant);
+        }
+
+        $rectorConfigBuilder = new RectorConfigBuilder()
+            ->withComposerBased(laravel: true, drupal: true);
+
+        self::assertSame([SetGroup::LARAVEL, SetGroup::DRUPAL], $this->readPrivateArray($rectorConfigBuilder, 'setGroups'));
+        self::assertSame([], $this->readPrivateArray($rectorConfigBuilder, 'sets'));
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    private function provideExtensionComposerBasedSetLists(): array
+    {
+        $extensionSetLists = new ReflectionClass(RectorConfigBuilder::class)
+            ->getConstant('EXTENSION_COMPOSER_BASED_SET_LISTS');
+
+        self::assertIsArray($extensionSetLists);
+
+        return $extensionSetLists;
+    }
+
+    /**
+     * @return mixed[]
+     */
+    private function readPrivateArray(RectorConfigBuilder $rectorConfigBuilder, string $propertyName): array
+    {
+        $value = new ReflectionClass($rectorConfigBuilder)
+            ->getProperty($propertyName)
+            ->getValue($rectorConfigBuilder);
+
+        self::assertIsArray($value);
+
+        return $value;
+    }
+}