diff --git a/Admin/Routes/Web/Backend.php b/Admin/Routes/Web/Backend.php
index fdc70cb..1a20031 100644
--- a/Admin/Routes/Web/Backend.php
+++ b/Admin/Routes/Web/Backend.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 use Modules\Knowledgebase\Controller\BackendController;
 use Modules\Knowledgebase\Models\PermissionState;
diff --git a/Theme/Backend/Lang/Navigation.en.lang.php b/Theme/Backend/Lang/Navigation.en.lang.php
index ff80332..f222d78 100644
--- a/Theme/Backend/Lang/Navigation.en.lang.php
+++ b/Theme/Backend/Lang/Navigation.en.lang.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *
diff --git a/Theme/Backend/Lang/en.lang.php b/Theme/Backend/Lang/en.lang.php
index 67d0804..2c3703c 100644
--- a/Theme/Backend/Lang/en.lang.php
+++ b/Theme/Backend/Lang/en.lang.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *
diff --git a/Theme/Backend/wiki-category-list.tpl.php b/Theme/Backend/wiki-category-list.tpl.php
index 69c1c05..319ac24 100644
--- a/Theme/Backend/wiki-category-list.tpl.php
+++ b/Theme/Backend/wiki-category-list.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *
diff --git a/Theme/Backend/wiki-category-single.tpl.php b/Theme/Backend/wiki-category-single.tpl.php
index 17f1c45..262ffcf 100644
--- a/Theme/Backend/wiki-category-single.tpl.php
+++ b/Theme/Backend/wiki-category-single.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * @var \phpOMS\Views\View $this
  */
diff --git a/Theme/Backend/wiki-dashboard.tpl.php b/Theme/Backend/wiki-dashboard.tpl.php
index 1804ad1..7c7563f 100644
--- a/Theme/Backend/wiki-dashboard.tpl.php
+++ b/Theme/Backend/wiki-dashboard.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 $categories = $this->getData('categories');
 echo $this->getData('nav')->render(); ?>
 
diff --git a/Theme/Backend/wiki-doc.tpl.php b/Theme/Backend/wiki-doc.tpl.php
index 74da3d8..3ddcd9b 100644
--- a/Theme/Backend/wiki-doc.tpl.php
+++ b/Theme/Backend/wiki-doc.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 $doc = $this->getData('doc');