diff --git a/CHANGELOG.md b/CHANGELOG.md
index e78c3e0..73629a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [10.1.5] - 2023.09.15
+### Fixed
+- Added missing null check for optional nullable object mapping
+
 ## [10.1.4] - 2023.08.25
 ### Fixed
 - Avoid new DateTimeImmutable(null) - adding support for nullable optional datetime
diff --git a/src/Generator/SchemaMapperGenerator.php b/src/Generator/SchemaMapperGenerator.php
index 86b9dff..8a7c8aa 100644
--- a/src/Generator/SchemaMapperGenerator.php
+++ b/src/Generator/SchemaMapperGenerator.php
@@ -320,12 +320,24 @@ protected function generateMapStatementsForObject(Field $root, Variable $payload
 
             foreach ($optionalFields as $i => $field) {
                 if ($field->isComposite()) {
-                    $mapper      = $this->builder->localPropertyFetch(SchemaMapperNaming::getPropertyName($field));
-                    $optionalVar = $this->builder->methodCall(
-                        $mapper,
-                        'toSchema',
-                        [$optionalResponseItems[$i]]
-                    );
+                    $mapper = $this->builder->localPropertyFetch(SchemaMapperNaming::getPropertyName($field));
+                    if ($field->isNullable()) {
+                        $optionalVar = $this->builder->ternary(
+                            $this->builder->notEquals($optionalResponseItems[$i], $this->builder->val(null)),
+                            $this->builder->methodCall(
+                                $mapper,
+                                'toSchema',
+                                [$optionalResponseItems[$i]]
+                            ),
+                            $this->builder->val(null)
+                        );
+                    } else {
+                        $optionalVar = $this->builder->methodCall(
+                            $mapper,
+                            'toSchema',
+                            [$optionalResponseItems[$i]]
+                        );
+                    }
                 } elseif ($field->isDate()) {
                     $this->addImport(DateTimeImmutable::class);
                     if ($field->isNullable()) {
diff --git a/test/suite/functional/Generator/SchemaMapper/ItemMapper.php b/test/suite/functional/Generator/SchemaMapper/ItemMapper.php
index 846871e..283b6b1 100644
--- a/test/suite/functional/Generator/SchemaMapper/ItemMapper.php
+++ b/test/suite/functional/Generator/SchemaMapper/ItemMapper.php
@@ -63,6 +63,9 @@ public function toSchema(array $payload): Item
         if (isset($payload['optionalObject'])) {
             $schema->setOptionalObject($this->embeddedObjectMapper->toSchema($payload['optionalObject']));
         }
+        if (\array_key_exists('optionalNullableObject', $payload)) {
+            $schema->setOptionalNullableObject($payload['optionalNullableObject'] !== null ? $this->embeddedNullableObjectMapper->toSchema($payload['optionalNullableObject']) : null);
+        }
 
         return $schema;
     }
diff --git a/test/suite/functional/Generator/SchemaMapper/item.yaml b/test/suite/functional/Generator/SchemaMapper/item.yaml
index 2615401..2bce727 100644
--- a/test/suite/functional/Generator/SchemaMapper/item.yaml
+++ b/test/suite/functional/Generator/SchemaMapper/item.yaml
@@ -79,6 +79,8 @@ components:
             type: string
         optionalObject:
           $ref: '#/components/schemas/EmbeddedObject'
+        optionalNullableObject:
+          $ref: '#/components/schemas/EmbeddedNullableObject'
       required:
         - mandatoryInteger
         - mandatoryString