diff --git a/xExtension-CustomCSS/extension.php b/xExtension-CustomCSS/extension.php
index 6860e3d..1874eef 100644
--- a/xExtension-CustomCSS/extension.php
+++ b/xExtension-CustomCSS/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class CustomCSSExtension extends Minz_Extension {
 	public function init() {
 		$this->registerTranslates();
diff --git a/xExtension-CustomJS/extension.php b/xExtension-CustomJS/extension.php
index db76899..f4fb5ad 100644
--- a/xExtension-CustomJS/extension.php
+++ b/xExtension-CustomJS/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class CustomJSExtension extends Minz_Extension {
 	public function init() {
 		$this->registerTranslates();
diff --git a/xExtension-ImageProxy/extension.php b/xExtension-ImageProxy/extension.php
index 2e9e3c9..f2cc09a 100644
--- a/xExtension-ImageProxy/extension.php
+++ b/xExtension-ImageProxy/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class ImageProxyExtension extends Minz_Extension {
 	// Defaults
 	const PROXY_URL = 'https://images.weserv.nl/?url=';
diff --git a/xExtension-QuickCollapse/extension.php b/xExtension-QuickCollapse/extension.php
index 2b4531f..8f8e425 100644
--- a/xExtension-QuickCollapse/extension.php
+++ b/xExtension-QuickCollapse/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class QuickCollapseExtension extends Minz_Extension {
 	public function init() {
 		$this->registerTranslates();
diff --git a/xExtension-ReadingTime/extension.php b/xExtension-ReadingTime/extension.php
index b8fbf4c..3cb3f19 100644
--- a/xExtension-ReadingTime/extension.php
+++ b/xExtension-ReadingTime/extension.php
@@ -1,4 +1,6 @@
 <?php
+
+declare(strict_types=1);
 class ReadingTimeExtension extends Minz_Extension {
 	public function init() {
 		Minz_View::appendScript($this->getFileUrl('readingtime.js', 'js'));
diff --git a/xExtension-ShareByEmail/extension.php b/xExtension-ShareByEmail/extension.php
index 5000da6..5e5ed4f 100644
--- a/xExtension-ShareByEmail/extension.php
+++ b/xExtension-ShareByEmail/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class ShareByEmailExtension extends Minz_Extension {
 	public function init() {
 		$this->registerTranslates();
diff --git a/xExtension-StickyFeeds/extension.php b/xExtension-StickyFeeds/extension.php
index 862d7e8..e5365ce 100644
--- a/xExtension-StickyFeeds/extension.php
+++ b/xExtension-StickyFeeds/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class StickyFeedsExtension extends Minz_Extension {
 	public function init() {
 		Minz_View::appendStyle($this->getFileUrl('style.css', 'css'));
diff --git a/xExtension-TTRSS_API/extension.php b/xExtension-TTRSS_API/extension.php
index 8533149..87004c0 100644
--- a/xExtension-TTRSS_API/extension.php
+++ b/xExtension-TTRSS_API/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class TTRSS_APIExtension extends Minz_Extension {
 	public function init() {
 		$this->registerHook('post_update',
diff --git a/xExtension-TitleWrap/extension.php b/xExtension-TitleWrap/extension.php
index 36a028e..c33ce8d 100644
--- a/xExtension-TitleWrap/extension.php
+++ b/xExtension-TitleWrap/extension.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class TitleWrapExtension extends Minz_Extension {
 	public function init() {
                 Minz_View::appendStyle($this->getFileUrl('title_wrap.css', 'css'));
diff --git a/xExtension-showFeedID/extension.php b/xExtension-showFeedID/extension.php
index 1809fbb..b17e37f 100644
--- a/xExtension-showFeedID/extension.php
+++ b/xExtension-showFeedID/extension.php
@@ -1,4 +1,7 @@
 <?php
+
+declare(strict_types=1);
+
 class ShowFeedIdExtension extends Minz_Extension {
 	public function init() {
 		Minz_View::appendScript($this->getFileUrl('showfeedid.js', 'js'));