diff --git a/typo3/sysext/adminpanel/ext_localconf.php b/typo3/sysext/adminpanel/ext_localconf.php
index 47228df1e9443aa9dc412db704a074c61a793429..132809c3abb3b198ea77865b423a886a86bf76e0 100644
--- a/typo3/sysext/adminpanel/ext_localconf.php
+++ b/typo3/sysext/adminpanel/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['adminpanel']['modules'] = [
diff --git a/typo3/sysext/backend/ext_localconf.php b/typo3/sysext/backend/ext_localconf.php
index 2739f013e6cfb03c1c937efd1b69c412fb6f595b..8f138df4c9aefa8bc4e44b842ea253fb89ead2e5 100644
--- a/typo3/sysext/backend/ext_localconf.php
+++ b/typo3/sysext/backend/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['BE']['toolbarItems'][1435433106] = \TYPO3\CMS\Backend\Backend\ToolbarItems\ClearCacheToolbarItem::class;
diff --git a/typo3/sysext/core/ext_localconf.php b/typo3/sysext/core/ext_localconf.php
index 971b809d0aba0863f5365436ab85fb4087cc0704..ee3ebb76e3b6cb60f150f75b4a4bf0819fa4768d 100644
--- a/typo3/sysext/core/ext_localconf.php
+++ b/typo3/sysext/core/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS'][\TYPO3\CMS\Core\Utility\GeneralUtility::class]['moveUploadedFile'][] = \TYPO3\CMS\Core\Resource\Security\SvgHookHandler::class . '->processMoveUploadedFile';
diff --git a/typo3/sysext/dashboard/ext_localconf.php b/typo3/sysext/dashboard/ext_localconf.php
index c0fc3acef07176ed67f0c55f2b8639d25ee38c3c..b3a9d5164eec6ebb4d416ac1253b4583589bee42 100644
--- a/typo3/sysext/dashboard/ext_localconf.php
+++ b/typo3/sysext/dashboard/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 if (!is_array($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['dashboard_rss'] ?? null)) {
diff --git a/typo3/sysext/extbase/ext_localconf.php b/typo3/sysext/extbase/ext_localconf.php
index db083e9274baae88abbe7204725419d6fdd78bba..e6845e756a8918aeb768002e805df550c7aae0c0 100644
--- a/typo3/sysext/extbase/ext_localconf.php
+++ b/typo3/sysext/extbase/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Register type converters
diff --git a/typo3/sysext/extensionmanager/ext_localconf.php b/typo3/sysext/extensionmanager/ext_localconf.php
index 48497171a6351bc01858c1e3e09321d52b312fd2..a796e6dd0dec5574be4abc216c038d36f0ca35a4 100644
--- a/typo3/sysext/extensionmanager/ext_localconf.php
+++ b/typo3/sysext/extensionmanager/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Register extension list update task
diff --git a/typo3/sysext/felogin/ext_localconf.php b/typo3/sysext/felogin/ext_localconf.php
index 29666477b14946af6bb3fc0c6eb9dcf574248d40..2319fdadd1d2d42ae7a8d785eb2313082c779b24 100644
--- a/typo3/sysext/felogin/ext_localconf.php
+++ b/typo3/sysext/felogin/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Add default TypoScript
diff --git a/typo3/sysext/filelist/ext_localconf.php b/typo3/sysext/filelist/ext_localconf.php
index f1ee01b8ee1f3805ec43e87b0aa11dd3ee4a81cc..6c6304836f11a4df1e5db17e5357dc16addd2533 100644
--- a/typo3/sysext/filelist/ext_localconf.php
+++ b/typo3/sysext/filelist/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['BE']['ContextMenu']['ItemProviders'][1486418731] = \TYPO3\CMS\Filelist\ContextMenu\ItemProviders\FileProvider::class;
diff --git a/typo3/sysext/fluid_styled_content/ext_localconf.php b/typo3/sysext/fluid_styled_content/ext_localconf.php
index aae806acd547a135bdac88ff20f217b72f345687..22498d5d9645e11409af4b95179c92ddffb82543 100644
--- a/typo3/sysext/fluid_styled_content/ext_localconf.php
+++ b/typo3/sysext/fluid_styled_content/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Define TypoScript as content rendering template
diff --git a/typo3/sysext/form/ext_localconf.php b/typo3/sysext/form/ext_localconf.php
index 1ce048f510328215d5420dfba2c74e9dbde0cd08..5c5c97fbb57ef317a2ef9c4f29467ea96879afb1 100644
--- a/typo3/sysext/form/ext_localconf.php
+++ b/typo3/sysext/form/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 call_user_func(function () {
diff --git a/typo3/sysext/frontend/ext_localconf.php b/typo3/sysext/frontend/ext_localconf.php
index 38b65572f88305e4e3c80205daf45860def48d8c..b840aacac556e29e46263d9cba7acdeeba8fc049 100644
--- a/typo3/sysext/frontend/ext_localconf.php
+++ b/typo3/sysext/frontend/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Register all available content objects
diff --git a/typo3/sysext/impexp/ext_localconf.php b/typo3/sysext/impexp/ext_localconf.php
index bf01ba88a6ab95ed063f3084e8a9080a0ad1f0bd..54dc62837c928453510aed1a57681dcaa41f63b9 100644
--- a/typo3/sysext/impexp/ext_localconf.php
+++ b/typo3/sysext/impexp/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['typo3/backend.php']['constructPostProcess'][] = \TYPO3\CMS\Impexp\Hook\BackendControllerHook::class . '->addJavaScript';
diff --git a/typo3/sysext/indexed_search/ext_localconf.php b/typo3/sysext/indexed_search/ext_localconf.php
index 693b977a77e7f54029da622d0b764b9eeeca7608..e46ba61a2e6e872433a8f88e720195439a11a5d6 100644
--- a/typo3/sysext/indexed_search/ext_localconf.php
+++ b/typo3/sysext/indexed_search/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // register plugin
diff --git a/typo3/sysext/install/ext_localconf.php b/typo3/sysext/install/ext_localconf.php
index b1f18aa9f9e48d0a2e91e69fe06efa8e8185b5b8..4ce49fe9b3c76640f141c746b492accf852ed493 100644
--- a/typo3/sysext/install/ext_localconf.php
+++ b/typo3/sysext/install/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // v9->v10 wizards below this line
diff --git a/typo3/sysext/linkvalidator/ext_localconf.php b/typo3/sysext/linkvalidator/ext_localconf.php
index 4880a2c6095250d37cc6ce1a55f7b5c8b87db27f..0e29b59d17151cfb206f5342a47d350a6a661f18 100644
--- a/typo3/sysext/linkvalidator/ext_localconf.php
+++ b/typo3/sysext/linkvalidator/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
diff --git a/typo3/sysext/opendocs/ext_localconf.php b/typo3/sysext/opendocs/ext_localconf.php
index 9148efb3ffc5243484236e817e884805296e29e5..b2e9e1ef004a50e493d46babbfc75e1b28f8b1be 100644
--- a/typo3/sysext/opendocs/ext_localconf.php
+++ b/typo3/sysext/opendocs/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['BE']['toolbarItems'][1435433112] = \TYPO3\CMS\Opendocs\Backend\ToolbarItems\OpendocsToolbarItem::class;
diff --git a/typo3/sysext/recordlist/ext_localconf.php b/typo3/sysext/recordlist/ext_localconf.php
index 5ff3ee58315e7a341aec0791359c5d9d33122de3..36beece8603f35a204c1c3e503cb4a0596c9678b 100644
--- a/typo3/sysext/recordlist/ext_localconf.php
+++ b/typo3/sysext/recordlist/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Register element browsers
diff --git a/typo3/sysext/recycler/ext_localconf.php b/typo3/sysext/recycler/ext_localconf.php
index 2eaf62f6993a027821996eaf3ce3eeb6f8883be2..3aea9703164bf94fec5a97b99f197d4c5220e5f7 100644
--- a/typo3/sysext/recycler/ext_localconf.php
+++ b/typo3/sysext/recycler/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['scheduler']['tasks'][\TYPO3\CMS\Recycler\Task\CleanerTask::class] = [
diff --git a/typo3/sysext/redirects/ext_localconf.php b/typo3/sysext/redirects/ext_localconf.php
index dc22cc9538d7a6eb53f4eb0af3f9e38a743201c8..5f668f794b7218e8490b59effa7ccde9d36fd55e 100644
--- a/typo3/sysext/redirects/ext_localconf.php
+++ b/typo3/sysext/redirects/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Rebuild cache in DataHandler on changing / inserting / adding redirect records
diff --git a/typo3/sysext/reports/ext_localconf.php b/typo3/sysext/reports/ext_localconf.php
index f962a21a666d2e5f49743c9f83658b2425f6cec7..fdc0d29062704fd7fd4003c48eedeafeb9eefa56 100644
--- a/typo3/sysext/reports/ext_localconf.php
+++ b/typo3/sysext/reports/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['scheduler']['tasks'][\TYPO3\CMS\Reports\Task\SystemStatusUpdateTask::class] = [
diff --git a/typo3/sysext/rte_ckeditor/ext_localconf.php b/typo3/sysext/rte_ckeditor/ext_localconf.php
index 470babe894133d852c2efe133a0c800005d68063..dc5e83e152290a09e76c6fdf405b527d9d2aaab6 100644
--- a/typo3/sysext/rte_ckeditor/ext_localconf.php
+++ b/typo3/sysext/rte_ckeditor/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Register FormEngine node type resolver hook to render RTE in FormEngine if enabled
diff --git a/typo3/sysext/scheduler/ext_localconf.php b/typo3/sysext/scheduler/ext_localconf.php
index b99bb4f0be34d70f24147cca192f48b00febec45..4b108e980a8abe1abaa5b2773df0982e2682cdcc 100644
--- a/typo3/sysext/scheduler/ext_localconf.php
+++ b/typo3/sysext/scheduler/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Get the extensions's configuration
diff --git a/typo3/sysext/seo/ext_localconf.php b/typo3/sysext/seo/ext_localconf.php
index 0f0eaad0f7bf5ada3a2195ef3cec56257059d6fc..dd77f34b8885068bbddadce1f78453292abaf57a 100644
--- a/typo3/sysext/seo/ext_localconf.php
+++ b/typo3/sysext/seo/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['TYPO3\CMS\Frontend\Page\PageGenerator']['generateMetaTags']['metatag'] =
diff --git a/typo3/sysext/sys_note/ext_localconf.php b/typo3/sysext/sys_note/ext_localconf.php
index ac6bad7ac45cdd2a4fdb13add365fda1dc149ca3..710bfae8a4b435603e9ecaa0cad8f56e8828bfa8 100644
--- a/typo3/sysext/sys_note/ext_localconf.php
+++ b/typo3/sysext/sys_note/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // Hook into the page modules
diff --git a/typo3/sysext/t3editor/ext_localconf.php b/typo3/sysext/t3editor/ext_localconf.php
index eec7794eacbfff1bb2e92da4081efa288c7b2a81..afa20f0e83a1752983af2afda70768c72bdca494 100644
--- a/typo3/sysext/t3editor/ext_localconf.php
+++ b/typo3/sysext/t3editor/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['typo3/file_edit.php']['preOutputProcessingHook'][] =
diff --git a/typo3/sysext/tstemplate/ext_localconf.php b/typo3/sysext/tstemplate/ext_localconf.php
index 505c2c915cb20200cd3733766a55f97795ca91a9..f4f725796574fc4c76d7e45f8ebd32c616b63ca7 100644
--- a/typo3/sysext/tstemplate/ext_localconf.php
+++ b/typo3/sysext/tstemplate/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearCachePostProc']['tstemplate'] = \TYPO3\CMS\Tstemplate\Hooks\DataHandlerClearCachePostProcHook::class . '->clearPageCacheIfNecessary';
diff --git a/typo3/sysext/workspaces/ext_localconf.php b/typo3/sysext/workspaces/ext_localconf.php
index 854f6b1eff06d8b0f5906104e3a6c66c09a1bcc0..a71ac144e573a36c67057ef2bef4a2d69721cdad 100644
--- a/typo3/sysext/workspaces/ext_localconf.php
+++ b/typo3/sysext/workspaces/ext_localconf.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 defined('TYPO3') or die();
 
 // add default notification options to every page