diff --git a/src/Attributes/LodataProperty.php b/src/Attributes/LodataProperty.php
index 63c5bd7db..67e8f6c44 100644
--- a/src/Attributes/LodataProperty.php
+++ b/src/Attributes/LodataProperty.php
@@ -6,6 +6,7 @@
 
 use Flat3\Lodata\Annotation\Core\V1\Computed;
 use Flat3\Lodata\Annotation\Core\V1\Description;
+use Flat3\Lodata\Annotation\Core\V1\Immutable;
 use Flat3\Lodata\DeclaredProperty;
 use Flat3\Lodata\EntitySet;
 use Flat3\Lodata\Property;
@@ -18,6 +19,7 @@ abstract class LodataProperty
     protected ?string $source = null;
     protected bool $key = false;
     protected bool $computed = false;
+    protected bool $immutable = false;
     protected bool $nullable = true;
     protected ?int $maxLength = null;
     protected ?int $precision = null;
@@ -38,13 +40,15 @@ public function __construct(
         $scale = null,
         $alternativeKey = false,
         $searchable = false,
-        $filterable = true
+        $filterable = true,
+        ?bool $immutable = false
     ) {
         $this->name = $name;
         $this->description = $description;
         $this->source = $source;
         $this->key = $key;
         $this->computed = $computed;
+        $this->immutable = $immutable;
         $this->nullable = $nullable;
         $this->maxLength = $maxLength;
         $this->precision = $precision;
@@ -84,6 +88,11 @@ public function isComputed(): bool
         return $this->computed;
     }
 
+    public function isImmutable(): bool
+    {
+        return $this->immutable;
+    }
+
     public function isNullable(): bool
     {
         return $this->nullable && !$this->key;
@@ -158,6 +167,10 @@ public function addProperty(EntitySet $entitySet): Property
             $property->addAnnotation(new Computed);
         }
 
+        if ($this->isImmutable()) {
+            $property->addAnnotation(new Immutable);
+        }
+
         if ($this->hasMaxLength()) {
             $property->setMaxLength($this->getMaxLength());
         }
@@ -178,4 +191,4 @@ public function addProperty(EntitySet $entitySet): Property
     }
 
     abstract public function getType(): Type;
-}
\ No newline at end of file
+}
diff --git a/src/Drivers/EloquentEntitySet.php b/src/Drivers/EloquentEntitySet.php
index 3a8560585..122adfb58 100644
--- a/src/Drivers/EloquentEntitySet.php
+++ b/src/Drivers/EloquentEntitySet.php
@@ -151,9 +151,7 @@ public function getModelByKey(PropertyValue $key): ?Model
      */
     public function getTable(): string
     {
-        $model = $this->getModel();
-
-        return $model->getTable();
+        return $this->getModel()->getTable();
     }
 
     /**
@@ -168,7 +166,7 @@ public function getConnection(): ConnectionInterface
     /**
      * Read an Eloquent model
      * @param  PropertyValue  $key  Model key
-     * @return Entity|null Entity
+     * @return Entity Entity
      */
     public function read(PropertyValue $key): Entity
     {
@@ -258,6 +256,10 @@ public function delete(PropertyValue $key): void
     {
         $model = $this->getModelByKey($key);
 
+        if (null === $model) {
+            throw new NotFoundException('entity_not_found', 'Entity not found');
+        }
+
         try {
             $model->delete();
         } catch (Exception $e) {
diff --git a/src/GeneratedProperty.php b/src/GeneratedProperty.php
index 4915b4965..e078d18bf 100644
--- a/src/GeneratedProperty.php
+++ b/src/GeneratedProperty.php
@@ -16,7 +16,7 @@ abstract class GeneratedProperty extends Property
     /**
      * Generate the property value for this property on the provided entity
      * @param  ComplexValue  $value  Entity this property is generated on
-     * @return PropertyValue
+     * @return Primitive|scalar|null
      */
     abstract public function invoke(ComplexValue $value);