diff --git a/composer.json b/composer.json
index f6057a9..9a7c880 100644
--- a/composer.json
+++ b/composer.json
@@ -18,6 +18,7 @@
     "php": ">=8.0",
     "doctrine/cache": "^1.11",
     "doctrine/common": "^3.1.0",
+    "friendsofphp/proxy-manager-lts": "^1.0",
     "php-arsenal/salesforce-bundle": "^4.0",
     "sensio/framework-extra-bundle": "^6.1.0",
     "symfony/dependency-injection": "^5.2",
diff --git a/src/Mapper.php b/src/Mapper.php
index 737efeb..6cb920d 100644
--- a/src/Mapper.php
+++ b/src/Mapper.php
@@ -14,6 +14,7 @@
 use PhpArsenal\SalesforceMapperBundle\Response\MappedRecordIterator;
 use PhpArsenal\SoapClient\ClientInterface;
 use PhpArsenal\SoapClient\Result;
+use ProxyManager\Configuration;
 use ReflectionClass;
 use ReflectionObject;
 use stdClass;
@@ -404,7 +405,7 @@ public function mapToSalesforceObject($model)
 
         /** @var Result\DescribeSObjectResult $objectDescription */
         $objectDescription = $this->getObjectDescription($model);
-        $reflClass = new ReflectionClass($model);
+        $reflClass = new ReflectionClass((new Configuration())->getClassNameInflector()->getUserClassName($model));
         $mappedProperties = $this->annotationReader->getSalesforceFields($model);
         $mappedRelations = $this->annotationReader->getSalesforceRelations($model);
         $allMappings = $mappedProperties->toArray() + $mappedRelations;