diff --git a/src/Module/DataType/ModuleDataType.php b/src/Module/DataType/ModuleDataType.php
index 93b14c1..d8cfa21 100644
--- a/src/Module/DataType/ModuleDataType.php
+++ b/src/Module/DataType/ModuleDataType.php
@@ -25,35 +25,35 @@ public function __construct(
         string $version,
         string $description,
         bool $active,
-        private readonly ?string $thumbnail,
-        private readonly ?string $author,
-        private readonly ?string $url,
-        private readonly ?string $email,
+        private readonly string $thumbnail,
+        private readonly string $author,
+        private readonly string $url,
+        private readonly string $email,
         private readonly string $lang
     ) {
         parent::__construct($id, $title, $version, $description, $active);
     }
 
     #[Field]
-    public function getThumbnail(): ?string
+    public function getThumbnail(): string
     {
         return $this->thumbnail;
     }
 
     #[Field]
-    public function getAuthor(): ?string
+    public function getAuthor(): string
     {
         return $this->author;
     }
 
     #[Field]
-    public function getUrl(): ?string
+    public function getUrl(): string
     {
         return $this->url;
     }
 
     #[Field]
-    public function getEmail(): ?string
+    public function getEmail(): string
     {
         return $this->email;
     }
diff --git a/src/Module/DataType/ModuleDataTypeInterface.php b/src/Module/DataType/ModuleDataTypeInterface.php
index 2844785..6da40b9 100644
--- a/src/Module/DataType/ModuleDataTypeInterface.php
+++ b/src/Module/DataType/ModuleDataTypeInterface.php
@@ -15,16 +15,16 @@
 interface ModuleDataTypeInterface extends ComponentDataTypeInterface
 {
     #[Field]
-    public function getThumbnail(): ?string;
+    public function getThumbnail(): string;
 
     #[Field]
-    public function getAuthor(): ?string;
+    public function getAuthor(): string;
 
     #[Field]
-    public function getUrl(): ?string;
+    public function getUrl(): string;
 
     #[Field]
-    public function getEmail(): ?string;
+    public function getEmail(): string;
 
     #[Field]
     public function getLang(): string;