diff --git a/src/Doctrine/PersistentTranslatable.php b/src/Doctrine/PersistentTranslatable.php
index a78d7aa..ba21eb8 100644
--- a/src/Doctrine/PersistentTranslatable.php
+++ b/src/Doctrine/PersistentTranslatable.php
@@ -13,6 +13,7 @@
 use Doctrine\Common\Collections\Selectable;
 use Doctrine\ORM\UnitOfWork;
 use Exception;
+use InvalidArgumentException;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
 use ReflectionClass;
@@ -97,6 +98,10 @@ public function __construct(
             $this->valueForEjection = $currentValue;
         } elseif ($currentValue instanceof Translatable) {
             $currentValue->copy($this);
+
+            if (!isset($this->primaryValue) && !(new ReflectionProperty($this, 'primaryValue'))->isInitialized($this)) {
+                throw new InvalidArgumentException('An object of class '.$class.' has no value set (not even NULL) for the property "'.$this->translatedProperty->getName().'" for the primary locale "'.$primaryLocale.'" configured for this class (e.g. via `#[Polyglot\Locale(primary: "'.$primaryLocale.'")]`). Check any assignments of `new Translatable`s to the property "'.$this->translatedProperty->getName().'": If a $locale is passed, it differs from the primary locale configured the class ("'.$primaryLocale.'"). If no $locale is passed, the primary locale configured the class ("'.$primaryLocale.'") differs from the application default locale (configured via `webfactory_polyglot.defaultLocale`).');
+            }
         } else {
             $this->primaryValue = $currentValue;
         }