diff --git a/src/Repository/RelationBuilder.php b/src/Repository/RelationBuilder.php
index 4fa2f1d..07f6c76 100644
--- a/src/Repository/RelationBuilder.php
+++ b/src/Repository/RelationBuilder.php
@@ -109,7 +109,13 @@ class RelationBuilder
 
                     $this->entity->eventExecute(Event\EntityRelationLoadInterface::class, $name, $this->repository);
 
-                    return call_user_func([ $this->repository, $relation->function() ]) ?? $this->instanciateEmptyEntity($name, $relation);
+                    $value = call_user_func([ $this->repository, $relation->function() ]) ?? null;
+
+                    if ($value === null && $this->resolver->reflectedClass->getProperties(true)[$name]->allowsNull()) {
+                        return null;
+                    }
+
+                    return $value ?? $this->instanciateEmptyEntity($name, $relation);
 
                 case $relation->isOneToMany():
                     $this->oneToMany($name, $relation);