diff --git a/src/Class/Schema/ClassDefinition.php b/src/Class/Schema/ClassDefinition.php
index 1e2875dc8..06df462f0 100644
--- a/src/Class/Schema/ClassDefinition.php
+++ b/src/Class/Schema/ClassDefinition.php
@@ -75,7 +75,7 @@ public function __construct(
         #[Property(description: 'Modification date timestamp', type: 'integer', example: 1700000000)]
         private readonly ?int $modificationDate,
         #[Property(description: 'User id of owner', type: 'integer', example: 1)]
-        private readonly int $userOwner,
+        private readonly ?int $userOwner,
         #[Property(
             description: 'Namespace of parent class',
             type: 'string',
@@ -175,7 +175,7 @@ public function getModificationDate(): ?int
         return $this->modificationDate;
     }
 
-    public function getUserOwner(): int
+    public function getUserOwner(): ?int
     {
         return $this->userOwner;
     }
diff --git a/src/Class/Schema/CustomLayout/CustomLayout.php b/src/Class/Schema/CustomLayout/CustomLayout.php
index 6a953a4c4..c7a65bebb 100644
--- a/src/Class/Schema/CustomLayout/CustomLayout.php
+++ b/src/Class/Schema/CustomLayout/CustomLayout.php
@@ -54,7 +54,7 @@ public function __construct(
         #[Property(description: 'Modification date timestamp', type: 'integer', example: 1633036800)]
         private readonly int $modificationDate,
         #[Property(description: 'User id of owner', type: 'integer', example: 1)]
-        private readonly int $userOwner,
+        private readonly ?int $userOwner,
         #[Property(description: 'Class id', type: 'string', example: 'Product')]
         private readonly string $classId,
         #[Property(description: 'Whether it is the default layout', type: 'boolean', example: false)]
@@ -94,7 +94,7 @@ public function getModificationDate(): int
         return $this->modificationDate;
     }
 
-    public function getUserOwner(): int
+    public function getUserOwner(): ?int
     {
         return $this->userOwner;
     }