diff --git a/Admin/Routes/Web/Backend.php b/Admin/Routes/Web/Backend.php
index 8b8ad43..f028633 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\SupplierManagement\Controller\BackendController;
 use Modules\SupplierManagement\Models\PermissionState;
diff --git a/Theme/Backend/Lang/Navigation.en.lang.php b/Theme/Backend/Lang/Navigation.en.lang.php
index 4f35bc0..41a8b8e 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 a7e2539..52b242e 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/supplier-create.tpl.php b/Theme/Backend/supplier-create.tpl.php
index 0dffbde..6c30f07 100644
--- a/Theme/Backend/supplier-create.tpl.php
+++ b/Theme/Backend/supplier-create.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *
diff --git a/Theme/Backend/supplier-list.tpl.php b/Theme/Backend/supplier-list.tpl.php
index cf20b4e..264a879 100644
--- a/Theme/Backend/supplier-list.tpl.php
+++ b/Theme/Backend/supplier-list.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *
diff --git a/Theme/Backend/supplier-single.tpl.php b/Theme/Backend/supplier-single.tpl.php
index bc5d7d7..118758c 100644
--- a/Theme/Backend/supplier-single.tpl.php
+++ b/Theme/Backend/supplier-single.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * Orange Management
  *