diff --git a/lib/Doctrine/ORM/Exception/EntityIdentityCollisionException.php b/lib/Doctrine/ORM/Exception/EntityIdentityCollisionException.php
new file mode 100644
index 00000000000..a70108c6f56
--- /dev/null
+++ b/lib/Doctrine/ORM/Exception/EntityIdentityCollisionException.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ORM\Exception;
+
+use function get_class;
+use function sprintf;
+
+final class EntityIdentityCollisionException extends ORMException
+{
+    /**
+     * @param object $existingEntity
+     * @param object $newEntity
+     */
+    public static function create($existingEntity, $newEntity, string $idHash): self
+    {
+        return new self(
+            sprintf(
+                <<<'EXCEPTION'
+While adding an entity of class %s with an ID hash of "%s" to the identity map,
+another object of class %s was already present for the same ID. This exception
+is a safeguard against an internal inconsistency - IDs should uniquely map to
+entity object instances. This problem may occur if:
+
+- you use application-provided IDs and reuse ID values;
+- database-provided IDs are reassigned after truncating the database without
+clearing the EntityManager;
+- you might have been using EntityManager#getReference() to create a reference
+for a nonexistent ID that was subsequently (by the RDBMS) assigned to another
+entity.
+
+Otherwise, it might be an ORM-internal inconsistency, please report it.
+EXCEPTION
+                ,
+                get_class($newEntity),
+                $idHash,
+                get_class($existingEntity)
+            )
+        );
+    }
+}
diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 64ca810e78b..15997e83d73 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -23,6 +23,7 @@
 use Doctrine\ORM\Event\PrePersistEventArgs;
 use Doctrine\ORM\Event\PreRemoveEventArgs;
 use Doctrine\ORM\Event\PreUpdateEventArgs;
+use Doctrine\ORM\Exception\EntityIdentityCollisionException;
 use Doctrine\ORM\Exception\ORMException;
 use Doctrine\ORM\Exception\UnexpectedAssociationValue;
 use Doctrine\ORM\Id\AssignedGenerator;
@@ -1624,6 +1625,7 @@ public function isEntityScheduled($entity)
      * the entity in question is already managed.
      *
      * @throws ORMInvalidArgumentException
+     * @throws EntityIdentityCollisionException
      *
      * @ignore
      */
@@ -1636,34 +1638,13 @@ public function addToIdentityMap($entity)
         if (isset($this->identityMap[$className][$idHash])) {
             if ($this->identityMap[$className][$idHash] !== $entity) {
                 if ($this->em->getConfiguration()->isRejectIdCollisionInIdentityMapEnabled()) {
-                    throw new RuntimeException(
-                        sprintf(
-                            <<<'EXCEPTION'
-While adding an entity of class %s with an ID hash of "%s" to the identity map,
-another object of class %s was already present for the same ID. This exception
-is a safeguard against an internal inconsistency - IDs should uniquely map to
-entity object instances. This problem may occur if:
-
-- you use application-provided IDs and reuse ID values;
-- database-provided IDs are reassigned after truncating the database without 
-  clearing the EntityManager;
-- you might have been using EntityManager#getReference() to create a reference 
-  for a nonexistent ID that was subsequently (by the RDBMS) assigned to another 
-  entity. 
+                    throw EntityIdentityCollisionException::create($this->identityMap[$className][$idHash], $entity, $idHash);
+                }
 
-Otherwise, it might be an ORM-internal inconsistency, please report it. 
-EXCEPTION
-                            ,
-                            get_class($entity),
-                            $idHash,
-                            get_class($this->identityMap[$className][$idHash])
-                        )
-                    );
-                } else {
-                    Deprecation::trigger(
-                        'doctrine/orm',
-                        'https://github.com/doctrine/orm/pull/10785',
-                        <<<'EXCEPTION'
+                Deprecation::trigger(
+                    'doctrine/orm',
+                    'https://github.com/doctrine/orm/pull/10785',
+                    <<<'EXCEPTION'
 While adding an entity of class %s with an ID hash of "%s" to the identity map,
 another object of class %s was already present for the same ID. This will trigger
 an exception in ORM 3.0.
@@ -1683,12 +1664,11 @@ public function addToIdentityMap($entity)
 \Doctrine\ORM\Configuration::setRejectIdCollisionInIdentityMap on the entity
 manager's configuration.
 EXCEPTION
-                        ,
-                        get_class($entity),
-                        $idHash,
-                        get_class($this->identityMap[$className][$idHash])
-                    );
-                }
+                    ,
+                    get_class($entity),
+                    $idHash,
+                    get_class($this->identityMap[$className][$idHash])
+                );
             }
 
             return false;
diff --git a/tests/Doctrine/Tests/ORM/Functional/BasicFunctionalTest.php b/tests/Doctrine/Tests/ORM/Functional/BasicFunctionalTest.php
index 2be3feba4ed..cfd60ab8cdc 100644
--- a/tests/Doctrine/Tests/ORM/Functional/BasicFunctionalTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/BasicFunctionalTest.php
@@ -5,6 +5,7 @@
 namespace Doctrine\Tests\ORM\Functional;
 
 use Doctrine\ORM\EntityNotFoundException;
+use Doctrine\ORM\Exception\EntityIdentityCollisionException;
 use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\ORMInvalidArgumentException;
 use Doctrine\ORM\PersistentCollection;
@@ -20,7 +21,6 @@
 use Doctrine\Tests\Models\CMS\CmsUser;
 use Doctrine\Tests\OrmFunctionalTestCase;
 use InvalidArgumentException;
-use RuntimeException;
 
 use function get_class;
 
@@ -1347,7 +1347,7 @@ public function testItThrowsWhenReferenceUsesIdAssignedByDatabase(): void
 
         // Now the database will assign an ID to the $user2 entity, but that place
         // in the identity map is already taken by user error.
-        $this->expectException(RuntimeException::class);
+        $this->expectException(EntityIdentityCollisionException::class);
         $this->expectExceptionMessageMatches('/another object .* was already present for the same ID/');
 
         // depending on ID generation strategy, the ID may be asssigned already here
diff --git a/tests/Doctrine/Tests/ORM/UnitOfWorkTest.php b/tests/Doctrine/Tests/ORM/UnitOfWorkTest.php
index 31fa5ea8f64..0569bfd06dd 100644
--- a/tests/Doctrine/Tests/ORM/UnitOfWorkTest.php
+++ b/tests/Doctrine/Tests/ORM/UnitOfWorkTest.php
@@ -13,6 +13,7 @@
 use Doctrine\Deprecations\PHPUnit\VerifyDeprecations;
 use Doctrine\ORM\EntityNotFoundException;
 use Doctrine\ORM\Events;
+use Doctrine\ORM\Exception\EntityIdentityCollisionException;
 use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Mapping\Column;
 use Doctrine\ORM\Mapping\Entity;
@@ -41,7 +42,6 @@
 use Doctrine\Tests\OrmTestCase;
 use Doctrine\Tests\PHPUnitCompatibility\MockBuilderCompatibilityTools;
 use PHPUnit\Framework\MockObject\MockObject;
-use RuntimeException;
 use stdClass;
 
 use function assert;
@@ -960,7 +960,7 @@ public function testItThrowsWhenApplicationProvidedIdsCollide(): void
         $phone2              = new CmsPhonenumber();
         $phone2->phonenumber = '1234';
 
-        $this->expectException(RuntimeException::class);
+        $this->expectException(EntityIdentityCollisionException::class);
         $this->expectExceptionMessageMatches('/another object .* was already present for the same ID/');
 
         $this->_unitOfWork->persist($phone2);