diff --git a/UPGRADE.md b/UPGRADE.md
index df6fcd889f6..05986037b5a 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -492,6 +492,10 @@ following classes and methods:
 
 Use `toIterable()` instead.
 
+## BC BREAK: `Doctrine\ORM\EntityManagerInterface#getReference()` and `getPartialReference()` does not return `null` anymore
+
+Method `Doctrine\ORM\EntityManagerInterface#getReference()` and `getPartialReference()` throws `InstanceOfTheWrongTypeEncountered` in 3.0 when different entity type is found in inheritance hierachy.
+
 # Upgrade to 2.14
 
 ## Deprecated annotation mapping driver.
diff --git a/lib/Doctrine/ORM/EntityManager.php b/lib/Doctrine/ORM/EntityManager.php
index 5621dd697d6..47f339fb4b8 100644
--- a/lib/Doctrine/ORM/EntityManager.php
+++ b/lib/Doctrine/ORM/EntityManager.php
@@ -12,6 +12,7 @@
 use Doctrine\DBAL\Exception as DBALException;
 use Doctrine\DBAL\LockMode;
 use Doctrine\ORM\Exception\EntityManagerClosed;
+use Doctrine\ORM\Exception\InstanceOfTheWrongTypeEncountered;
 use Doctrine\ORM\Exception\InvalidHydrationMode;
 use Doctrine\ORM\Exception\ManagerException;
 use Doctrine\ORM\Exception\MismatchedEventManager;
@@ -402,7 +403,11 @@ public function getReference(string $entityName, $id): object|null
 
         // Check identity map first, if its already in there just return it.
         if ($entity !== false) {
-            return $entity instanceof $class->name ? $entity : null;
+            if (! $entity instanceof $class->name) {
+                throw InstanceOfTheWrongTypeEncountered::forInstance($entity);
+            }
+
+            return $entity;
         }
 
         if ($class->subClasses) {
@@ -427,7 +432,11 @@ public function getPartialReference(string $entityName, $identifier): object|nul
 
         // Check identity map first, if its already in there just return it.
         if ($entity !== false) {
-            return $entity instanceof $class->name ? $entity : null;
+            if (! $entity instanceof $class->name) {
+                throw InstanceOfTheWrongTypeEncountered::forInstance($entity);
+            }
+
+            return $entity;
         }
 
         if (! is_array($identifier)) {
diff --git a/lib/Doctrine/ORM/EntityManagerInterface.php b/lib/Doctrine/ORM/EntityManagerInterface.php
index fa445f8572a..33990dc39f2 100644
--- a/lib/Doctrine/ORM/EntityManagerInterface.php
+++ b/lib/Doctrine/ORM/EntityManagerInterface.php
@@ -140,7 +140,7 @@ public function find(string $className, mixed $id, LockMode|int|null $lockMode =
      * @param mixed  $id         The entity identifier.
      * @psalm-param class-string<T> $entityName
      *
-     * @psalm-return T|null
+     * @psalm-return T
      *
      * @throws ORMException
      *
@@ -167,7 +167,7 @@ public function getReference(string $entityName, $id): object|null;
      * @param mixed  $identifier The entity identifier.
      * @psalm-param class-string<T> $entityName
      *
-     * @psalm-return T|null
+     * @psalm-return T
      *
      * @template T of object
      */
diff --git a/lib/Doctrine/ORM/Exception/InstanceOfTheWrongTypeEncountered.php b/lib/Doctrine/ORM/Exception/InstanceOfTheWrongTypeEncountered.php
new file mode 100644
index 00000000000..02eafa238d4
--- /dev/null
+++ b/lib/Doctrine/ORM/Exception/InstanceOfTheWrongTypeEncountered.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ORM\Exception;
+
+use LogicException;
+
+use function get_debug_type;
+
+final class InstanceOfTheWrongTypeEncountered extends LogicException implements ORMException
+{
+    /** @param object $instance */
+    public static function forInstance($instance): self
+    {
+        return new self('Instance of the wrong type (' . get_debug_type($instance) . ') was retrieved in inheritance hierachy.' .
+                        'This happens because identity map aggregates instances by rootEntityName ');
+    }
+}
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 9ef47050196..c2984d155b8 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -182,8 +182,8 @@
       <code>$entity</code>
       <code>$entity</code>
       <code>$entity</code>
-      <code>$entity instanceof $class-&gt;name ? $entity : null</code>
-      <code>$entity instanceof $class-&gt;name ? $entity : null</code>
+      <code>$entity</code>
+      <code>$entity</code>
       <code>$persister-&gt;load($sortedId, null, null, [], $lockMode)</code>
       <code>$persister-&gt;loadById($sortedId)</code>
       <code>$this-&gt;metadataFactory</code>
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1041Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1041Test.php
index 19f96242610..817c9ab99db 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1041Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC1041Test.php
@@ -4,6 +4,7 @@
 
 namespace Doctrine\Tests\ORM\Functional\Ticket;
 
+use Doctrine\ORM\Exception\InstanceOfTheWrongTypeEncountered;
 use Doctrine\Tests\Models\Company\CompanyFixContract;
 use Doctrine\Tests\Models\Company\CompanyFlexContract;
 use Doctrine\Tests\OrmFunctionalTestCase;
@@ -17,7 +18,7 @@ protected function setUp(): void
         parent::setUp();
     }
 
-    public function testGrabWrongSubtypeReturnsNull(): void
+    public function testGrabWrongSubtypeReturnsNullOrThrows(): void
     {
         $fix = new CompanyFixContract();
         $fix->setFixPrice(2000);
@@ -28,7 +29,15 @@ public function testGrabWrongSubtypeReturnsNull(): void
         $id = $fix->getId();
 
         self::assertNull($this->_em->find(CompanyFlexContract::class, $id));
-        self::assertNull($this->_em->getReference(CompanyFlexContract::class, $id));
-        self::assertNull($this->_em->getPartialReference(CompanyFlexContract::class, $id));
+
+        try {
+            $this->_em->getReference(CompanyFlexContract::class, $id);
+        } catch (InstanceOfTheWrongTypeEncountered) {
+        }
+
+        try {
+            $this->_em->getPartialReference(CompanyFlexContract::class, $id);
+        } catch (InstanceOfTheWrongTypeEncountered) {
+        }
     }
 }