diff --git a/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php b/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
index b38a212c9..1fd327be8 100644
--- a/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
+++ b/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
@@ -24,6 +24,8 @@ use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\Events;
 use Doctrine\ORM\Mapping\ClassMetadata;
 use PDO;
+use function array_map;
+use function in_array;
 
 /**
  * Base class for all hydrators. A hydrator is a class that provides some form
@@ -296,11 +298,9 @@ abstract class AbstractHydrator
 
                     // If there are field name collisions in the child class, then we need
                     // to only hydrate if we are looking at the correct discriminator value
-                    if(
-                        isset($cacheKeyInfo['discriminatorColumn']) && 
-                        isset($data[$cacheKeyInfo['discriminatorColumn']]) &&
+                    if (isset($cacheKeyInfo['discriminatorColumn'], $data[$cacheKeyInfo['discriminatorColumn']])
                         // Note: loose comparison required. See https://github.com/doctrine/doctrine2/pull/6304#issuecomment-323294442
-                        $data[$cacheKeyInfo['discriminatorColumn']] != $cacheKeyInfo['discriminatorValue']
+                        && ! in_array($data[$cacheKeyInfo['discriminatorColumn']], $cacheKeyInfo['discriminatorValues'])
                     ) {
                         break;
                     }
@@ -397,11 +397,21 @@ abstract class AbstractHydrator
                 // the current discriminator value must be saved in order to disambiguate fields hydration,
                 // should there be field name collisions
                 if ($classMetadata->parentClasses && isset($this->_rsm->discriminatorColumns[$ownerMap])) {
+                    $discriminatorValues = array_map(
+                        function (string $subClass) {
+                            return $this->getClassMetadata($subClass)->discriminatorValue;
+                        },
+                        $classMetadata->subClasses
+                    );
+
+                    $discriminatorValues[] = $classMetadata->discriminatorValue;
+
                     return $this->_cache[$key] = \array_merge(
                         $columnInfo,
                         [
                             'discriminatorColumn' => $this->_rsm->discriminatorColumns[$ownerMap],
-                            'discriminatorValue'  => $classMetadata->discriminatorValue
+                            'discriminatorValue'  => $classMetadata->discriminatorValue,
+                            'discriminatorValues' => $discriminatorValues,
                         ]
                     );
                 }