diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 19117ad..6d1c850 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,11 +8,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        TYPO3: [12, 13]
-        PHP: [ 8.2, 8.3 ]
-        include:
-          - TYPO3: 13
-            php: 8.4
+        TYPO3: [13, 14]
+        PHP: [ 8.2, 8.3, 8.4 ]
 
     steps:
       - name: Checkout
@@ -33,15 +30,15 @@ jobs:
           path: ~/.composer/cache
           key: dependencies-composer-${{ hashFiles('composer.json') }}
 
-      - name: Install composer dependencies TYPO3 13
-        if: matrix.TYPO3 == 13
+      - name: Install composer dependencies TYPO3 14
+        if: matrix.TYPO3 == 14
         run: |
           composer install --no-progress --no-interaction
 
-      - name: Install composer dependencies TYPO3 12
-        if: matrix.TYPO3 == 12
+      - name: Install composer dependencies TYPO3 13
+        if: matrix.TYPO3 == 13
         run: |
-          composer require typo3/cms-backend:^12.4 --no-progress --no-interaction --dev -W
+          composer require typo3/cms-backend:^13.4 --no-progress --no-interaction --dev
 
       - name: Phpstan
         run: .Build/bin/phpstan analyze -c Build/phpstan.neon
diff --git a/Classes/LinkHandler/PageLinkHandler.php b/Classes/LinkHandler/PageLinkHandler.php
index 75ffc67..f3f4dee 100644
--- a/Classes/LinkHandler/PageLinkHandler.php
+++ b/Classes/LinkHandler/PageLinkHandler.php
@@ -22,6 +22,7 @@
 use TYPO3\CMS\Core\Database\Query\Restriction\WorkspaceRestriction;
 use TYPO3\CMS\Core\Exception\SiteNotFoundException;
 use TYPO3\CMS\Core\Imaging\Icon;
+use TYPO3\CMS\Core\Imaging\IconSize;
 use TYPO3\CMS\Core\LinkHandling\LinkService;
 use TYPO3\CMS\Core\Site\Entity\SiteLanguage;
 use TYPO3\CMS\Core\Site\SiteFinder;
@@ -84,10 +85,12 @@ protected function getRecordsOnExpandedPage($pageId)
             $languages = $this->getAllLanguages($pageId);
             $availableLanguages = [];
             $languageIds = [];
+            $iconSizeSmall = class_exists(IconSize::class) ? IconSize::SMALL : constant(Icon::class . '::SIZE_SMALL');
+
             foreach ($languages as $language) {
                 $availableLanguages[$language->getLanguageId()] = [
                     'title' => $language->getTitle(),
-                    'flag' => $this->iconFactory->getIcon($language->getFlagIdentifier(), Icon::SIZE_SMALL),
+                    'flag' => $this->iconFactory->getIcon($language->getFlagIdentifier(), $iconSizeSmall),
                 ];
                 if ($language->getLanguageId() > -1) {
                     $availableLanguages[$language->getLanguageId()]['url'] = $this->linkService->asString([
@@ -113,7 +116,7 @@ protected function getRecordsOnExpandedPage($pageId)
                 $this->view->assign('activePageLink', $this->linkService->asString(['type' => LinkService::TYPE_PAGE, 'pageuid' => $pageId]));
             }
             $this->view->assign('activePageTitle', BackendUtility::getRecordTitle('pages', $activePageRecord, true));
-            $this->view->assign('activePageIcon', $this->iconFactory->getIconForRecord('pages', $activePageRecord, Icon::SIZE_SMALL)->render());
+            $this->view->assign('activePageIcon', $this->iconFactory->getIconForRecord('pages', $activePageRecord, $iconSizeSmall)->render());
 
             // Look up tt_content elements from the expanded page
             $queryBuilder = $this->connectionPool->getQueryBuilderForTable('tt_content');
@@ -156,7 +159,7 @@ protected function getRecordsOnExpandedPage($pageId)
             $groupedContentElements = [];
             $groupedContentElements[-1] = [
                 'label' => $languages[-1]['title'],
-                'flag' => $this->iconFactory->getIcon($languages[-1]['flagIcon'], Icon::SIZE_SMALL),
+                'flag' => $this->iconFactory->getIcon($languages[-1]['flagIcon'], $iconSizeSmall),
                 'items' => [],
             ];
             foreach ($contentElements as &$contentElement) {
@@ -164,7 +167,7 @@ protected function getRecordsOnExpandedPage($pageId)
                 if (!isset($groupedContentElements[$languageId])) {
                     $groupedContentElements[$languageId] = [
                         'label' => $languages[$languageId]['title'],
-                        'flag' => $this->iconFactory->getIcon($languages[$languageId]['flagIcon'], Icon::SIZE_SMALL),
+                        'flag' => $this->iconFactory->getIcon($languages[$languageId]['flagIcon'], $iconSizeSmall),
                         'items' => [],
                     ];
                 }
@@ -179,7 +182,7 @@ protected function getRecordsOnExpandedPage($pageId)
 
                 $contentElement['url'] = $this->linkService->asString(['type' => LinkService::TYPE_PAGE, 'parameters' => '&L=' . $languageId, 'pageuid' => (int)$pageId, 'fragment' => $contentElement['uid']]);
                 $contentElement['isSelected'] = !empty($this->linkParts) && (int)($this->linkParts['url']['fragment'] ?? 0) === (int)$contentElement['uid'];
-                $contentElement['icon'] = $this->iconFactory->getIconForRecord('tt_content', $contentElement, Icon::SIZE_SMALL)->render();
+                $contentElement['icon'] = $this->iconFactory->getIconForRecord('tt_content', $contentElement, $iconSizeSmall)->render();
                 $contentElement['title'] = BackendUtility::getRecordTitle('tt_content', $contentElement, true);
                 $groupedContentElements[$languageId]['items'][$colPos]['items'][] = $contentElement;
                 if ($languageId === 0) {
diff --git a/composer.json b/composer.json
index f0e6caa..a3ec484 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         "Language"
     ],
     "require": {
-        "typo3/cms-backend": "^12.4 || ^13.4"
+        "typo3/cms-backend": "^13.4 || ^14.3"
     },
     "autoload": {
         "psr-4": {
diff --git a/ext_emconf.php b/ext_emconf.php
index 3ccbbd2..927fa47 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -11,7 +11,7 @@
     'author_company' => 'b13 GmbH',
     'constraints' => [
         'depends' => [
-            'typo3' => '12.4.27-13.99.99',
+            'typo3' => '13.4.0-14.3.99',
         ],
     ],
 ];