diff --git a/Classes/Updates/PluginUpdater.php b/Classes/Updates/PluginUpdater.php
new file mode 100644
index 00000000..3ab3bfb5
--- /dev/null
+++ b/Classes/Updates/PluginUpdater.php
@@ -0,0 +1,275 @@
+<?php
+
+declare(strict_types=1);
+
+namespace HDNET\Calendarize\Updates;
+
+use TYPO3\CMS\Core\Configuration\FlexForm\FlexFormTools;
+use TYPO3\CMS\Core\Database\Connection;
+use TYPO3\CMS\Core\Database\Query\QueryBuilder;
+use TYPO3\CMS\Core\Database\Query\Restriction\DeletedRestriction;
+use TYPO3\CMS\Core\Service\FlexFormService;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Install\Attribute\UpgradeWizard;
+use TYPO3\CMS\Install\Updates\DatabaseUpdatedPrerequisite;
+
+#[UpgradeWizard('calendarize_pluginUpdater')]
+class PluginUpdater extends AbstractUpdate
+{
+    protected string $title = 'Calendarize Plugin Updater';
+
+    protected string $description = 'This wizard migrates the switchableControllerActions in all existing ' .
+        'plugins to the new list types. The permissions in BE groups are updated as well to allow all new ' .
+        'list types where necessary.';
+
+    protected array $migrationMap = [
+        'Calendar->list;Calendar->detail' => 'calendarize_listdetail',
+        'Calendar->list' => 'calendarize_list',
+        'Calendar->detail' => 'calendarize_detail',
+        'Calendar->search' => 'calendarize_search',
+        'Calendar->result' => 'calendarize_result',
+        'Calendar->latest' => 'calendarize_latest',
+        'Calendar->single' => 'calendarize_single',
+        'Calendar->year' => 'calendarize_year',
+        'Calendar->quarter' => 'calendarize_quarter',
+        'Calendar->month' => 'calendarize_month',
+        'Calendar->week' => 'calendarize_week',
+        'Calendar->day' => 'calendarize_day',
+        'Calendar->past' => 'calendarize_past',
+        'Booking->booking;Booking->send' => 'calendarize_booking',
+    ];
+
+    public function __construct(
+        protected readonly QueryBuilder $contentElementsQueryBuilder,
+        protected readonly QueryBuilder $backendGroupsQueryBuilder,
+        protected readonly FlexFormTools $flexFormTools,
+        protected readonly FlexFormService $flexFormService
+    ) {
+    }
+
+    /**
+     * @var string
+     */
+    public const OLD_LIST_TYPE = 'calendarize_calendar';
+
+    public function executeUpdate(): bool
+    {
+        $this->migratePlugins();
+        $this->migrateBackendUserGroupPermissions();
+
+        return true;
+    }
+
+    protected function migratePlugins(): void
+    {
+        $contentElements = $this->getContentElementsToMigrate();
+
+        $this->output->writeln('Start migration of ' . \count($contentElements) . ' plugins.');
+
+        foreach ($contentElements as $contentElement) {
+            $flexForm = $this->flexFormService->convertFlexFormContentToArray($contentElement['pi_flexform']);
+            $newListType = $this->getNewListType($flexForm['switchableControllerActions'] ?? '');
+            $flexFormData = $this->removeFlexFormSettingsNotForListType($contentElement, $newListType);
+
+            if (\count($flexFormData['data']) > 0) {
+                $newFlexform = $this->array2xml($flexFormData);
+            } else {
+                $newFlexform = '';
+            }
+
+            $this->updateContentElement($contentElement['uid'], $newListType, $newFlexform);
+        }
+
+        $this->output->writeln('');
+        $this->output->writeln('');
+        $this->output->writeln('Migration of plugins finished.');
+    }
+
+    protected function getContentElementsToMigrate(): array
+    {
+        $this->contentElementsQueryBuilder->getRestrictions()->removeAll()->add(
+            GeneralUtility::makeInstance(DeletedRestriction::class)
+        );
+        $constraintsForActions = [];
+        foreach ($this->migrationMap as $action => $_) {
+            $constraintsForActions[] = $this->contentElementsQueryBuilder->expr()->like(
+                'pi_flexform',
+                $this->contentElementsQueryBuilder->createNamedParameter(
+                    '%>' . $this->contentElementsQueryBuilder->escapeLikeWildcards(htmlspecialchars($action)) . '<%'
+                )
+            );
+        }
+
+        return $this->contentElementsQueryBuilder
+            ->select('uid', 'list_type', 'pi_flexform', 'pid', 'CType')
+            ->from('tt_content')
+            ->where(
+                $this->contentElementsQueryBuilder->expr()->eq(
+                    'CType',
+                    $this->contentElementsQueryBuilder->createNamedParameter('list')
+                ),
+                $this->contentElementsQueryBuilder->expr()->eq(
+                    'list_type',
+                    $this->contentElementsQueryBuilder->createNamedParameter(self::OLD_LIST_TYPE)
+                ),
+                $this->contentElementsQueryBuilder->expr()->or(...$constraintsForActions)
+            )
+            ->executeQuery()
+            ->fetchAllAssociative();
+    }
+
+    protected function getNewListType(string $actions): string
+    {
+        return $this->migrationMap[$actions] ?? self::OLD_LIST_TYPE;
+    }
+
+    protected function removeFlexFormSettingsNotForListType(array $contentElement, string $newListType): array
+    {
+        // Update record with new list_type (this is needed because FlexFormTools
+        // looks up those values in the given record and assumes they're up-to-date)
+        $contentElement['list_type'] = $newListType;
+        $newFlexform = $this->flexFormTools->cleanFlexFormXML('tt_content', 'pi_flexform', $contentElement);
+        $flexFormData = GeneralUtility::xml2array($newFlexform);
+
+        return $this->removeEmptyFlexFormSheets($flexFormData);
+    }
+
+    protected function removeEmptyFlexFormSheets(array $flexFormData): array
+    {
+        foreach ($flexFormData['data'] as $sheetKey => $sheetData) {
+            // Remove empty sheets
+            if (!\is_array($flexFormData['data'][$sheetKey]['lDEF']) || !\count($flexFormData['data'][$sheetKey]['lDEF']) > 0) {
+                unset($flexFormData['data'][$sheetKey]);
+            }
+        }
+
+        return $flexFormData;
+    }
+
+    protected function array2xml(array $input = []): string
+    {
+        $options = [
+            'parentTagMap' => [
+                'data' => 'sheet',
+                'sheet' => 'language',
+                'language' => 'field',
+                'el' => 'field',
+                'field' => 'value',
+                'field:el' => 'el',
+                'el:_IS_NUM' => 'section',
+                'section' => 'itemType',
+            ],
+            'disableTypeAttrib' => 2,
+        ];
+        $spaceInd = 4;
+        $output = GeneralUtility::array2xml($input, '', 0, 'T3FlexForms', $spaceInd, $options);
+
+        return '<?xml version="1.0" encoding="utf-8" standalone="yes" ?>' . LF . $output;
+    }
+
+    protected function updateContentElement(int $uid, string $newListType, string $flexform): void
+    {
+        $this->contentElementsQueryBuilder->update('tt_content')
+            ->set('list_type', $newListType)
+            ->set('pi_flexform', $flexform)
+            ->where(
+                $this->contentElementsQueryBuilder->expr()->in(
+                    'uid',
+                    $this->contentElementsQueryBuilder->createNamedParameter($uid, Connection::PARAM_INT)
+                )
+            )
+            ->executeStatement();
+    }
+
+    protected function migrateBackendUserGroupPermissions(): void
+    {
+        $groups = $this->getBackendUserGroupsToMigrate();
+        $this->output->writeln('');
+        $this->output->writeln('');
+        $this->output->writeln('Start migration of ' . \count($groups) . ' BE groups.');
+
+        foreach ($groups as $group) {
+            $this->updateBackendUserGroup($group);
+        }
+
+        $this->output->writeln('');
+        $this->output->writeln('');
+        $this->output->writeln('Migration of backend groups finished.');
+    }
+
+    protected function getBackendUserGroupsToMigrate(): array
+    {
+        $this->backendGroupsQueryBuilder->getRestrictions()->removeAll()->add(
+            GeneralUtility::makeInstance(DeletedRestriction::class)
+        );
+
+        return $this->backendGroupsQueryBuilder
+            ->select('uid', 'explicit_allowdeny')
+            ->from('be_groups')
+            ->where(
+                $this->backendGroupsQueryBuilder->expr()->like(
+                    'explicit_allowdeny',
+                    $this->backendGroupsQueryBuilder->createNamedParameter(
+                        '%' . $this->backendGroupsQueryBuilder->escapeLikeWildcards($this->getOldListTypeForGroupPermissions()) . '%'
+                    )
+                ),
+                $this->backendGroupsQueryBuilder->expr()->notLike(
+                    'explicit_allowdeny',
+                    $this->backendGroupsQueryBuilder->createNamedParameter(
+                        '%' . $this->backendGroupsQueryBuilder->escapeLikeWildcards($this->getNewListTypesForGroupPermissions()) . '%'
+                    )
+                )
+            )
+            ->executeQuery()
+            ->fetchAllAssociative();
+    }
+
+    protected function updateBackendUserGroup(array $group): void
+    {
+        $default = $this->getNewListTypesForGroupPermissions();
+
+        $searchReplace = [
+            $this->getOldListTypeForGroupPermissions() . ':ALLOW' => $default,
+            $this->getOldListTypeForGroupPermissions() . ':DENY' => '',
+            $this->getOldListTypeForGroupPermissions() => $default,
+        ];
+
+        $newList = str_replace(array_keys($searchReplace), array_values($searchReplace), $group['explicit_allowdeny']);
+        $this->backendGroupsQueryBuilder->update('be_groups')
+            ->set('explicit_allowdeny', $newList)
+            ->where(
+                $this->backendGroupsQueryBuilder->expr()->in(
+                    'uid',
+                    $this->backendGroupsQueryBuilder->createNamedParameter($group['uid'], Connection::PARAM_INT)
+                )
+            )
+            ->executeStatement();
+    }
+
+    protected function getOldListTypeForGroupPermissions(): string
+    {
+        return 'tt_content:list_type:' . self::OLD_LIST_TYPE;
+    }
+
+    protected function getNewListTypesForGroupPermissions(): string
+    {
+        $groupPermissions = $this->getOldListTypeForGroupPermissions();
+        foreach ($this->migrationMap as $newListType) {
+            $groupPermissions .= ',tt_content:list_type:' . $newListType;
+        }
+
+        return $groupPermissions;
+    }
+
+    public function updateNecessary(): bool
+    {
+        return \count($this->getContentElementsToMigrate()) > 0 || \count($this->getBackendUserGroupsToMigrate()) > 0;
+    }
+
+    public function getPrerequisites(): array
+    {
+        return [
+            DatabaseUpdatedPrerequisite::class,
+        ];
+    }
+}
diff --git a/Configuration/Services.yaml b/Configuration/Services.yaml
index 48274a18..b97fa662 100644
--- a/Configuration/Services.yaml
+++ b/Configuration/Services.yaml
@@ -86,3 +86,24 @@ services:
 
   HDNET\Calendarize\Service\PluginConfigurationService:
     public: true
+
+  QueryBuilder.tt_content:
+    class: 'TYPO3\CMS\Core\Database\Query\QueryBuilder'
+    factory:
+      - '@TYPO3\CMS\Core\Database\ConnectionPool'
+      - 'getQueryBuilderForTable'
+    arguments:
+      - 'tt_content'
+
+  QueryBuilder.be_groups:
+    class: 'TYPO3\CMS\Core\Database\Query\QueryBuilder'
+    factory:
+      - '@TYPO3\CMS\Core\Database\ConnectionPool'
+      - 'getQueryBuilderForTable'
+    arguments:
+      - 'be_groups'
+
+  HDNET\Calendarize\Updates\PluginUpdater:
+    arguments:
+      $contentElementsQueryBuilder: '@QueryBuilder.tt_content'
+      $backendGroupsQueryBuilder: '@QueryBuilder.be_groups'