diff --git a/features/main/patch.feature b/features/main/patch.feature
index eeddbc5a1e0..2d3f1e45a0e 100644
--- a/features/main/patch.feature
+++ b/features/main/patch.feature
@@ -30,7 +30,7 @@ Feature: Sending PATCH requets
     Then the JSON node "name" should not exist
 
   @createSchema
-  Scenario: Patch the relation
+  Scenario: Patch 1:1 relation
     Given there is a PatchDummyRelation
     When I add "Content-Type" header equal to "application/merge-patch+json"
     And I send a "PATCH" request to "/patch_dummy_relations/1" with body:
@@ -58,3 +58,44 @@ Feature: Sending PATCH requets
       }
     }
     """
+
+  @createSchema
+  Scenario: Patch 1:n relation
+    Given there is a PatchDummyRelation
+    When I add "Content-Type" header equal to "application/merge-patch+json"
+    And I send a "PATCH" request to "/patch_dummy_relations/1" with body:
+    """
+    {
+      "relatedDummies": [
+        {
+          "@id": "/related_dummies/2",
+          "symfony": "A new name"
+        }
+      ]
+    }
+    """
+    Then the response status code should be 200
+    And the response should be in JSON
+    And the header "Content-Type" should be equal to "application/ld+json; charset=utf-8"
+    And the JSON should be equal to:
+    """
+    {
+      "@context": "/contexts/PatchDummyRelation",
+      "@id": "/patch_dummy_relations/1",
+      "@type": "PatchDummyRelation",
+      "relatedDummies": [
+        {
+          "@id": "/related_dummies/1",
+          "@type": "https://schema.org/Product",
+          "id": 1,
+          "symfony": "symfony"
+        },
+        {
+          "@id": "/related_dummies/2",
+          "@type": "https://schema.org/Product",
+          "id": 2,
+          "symfony": "A new name"
+        }
+      ]
+    }
+    """
diff --git a/tests/Behat/DoctrineContext.php b/tests/Behat/DoctrineContext.php
index ba3c614b24a..0e276958f2d 100644
--- a/tests/Behat/DoctrineContext.php
+++ b/tests/Behat/DoctrineContext.php
@@ -1833,8 +1833,14 @@ public function thereIsAnInitializeInput(int $id)
     public function thereIsAPatchDummyRelation()
     {
         $dummy = $this->buildPatchDummyRelation();
-        $related = $this->buildRelatedDummy();
-        $dummy->setRelated($related);
+        $related1 = $this->buildRelatedDummy();
+        $dummy->setRelated($related1);
+
+        $related2 = $this->buildRelatedDummy();
+        $dummy->addRelatedDummy($related2);
+        $related3 = $this->buildRelatedDummy();
+        $dummy->addRelatedDummy($related3);
+
         $this->manager->persist($related);
         $this->manager->persist($dummy);
         $this->manager->flush();
diff --git a/tests/Fixtures/TestBundle/Entity/PatchDummyRelation.php b/tests/Fixtures/TestBundle/Entity/PatchDummyRelation.php
index aa830e506cc..4fe9c3c7bb9 100644
--- a/tests/Fixtures/TestBundle/Entity/PatchDummyRelation.php
+++ b/tests/Fixtures/TestBundle/Entity/PatchDummyRelation.php
@@ -14,6 +14,7 @@
 namespace ApiPlatform\Core\Tests\Fixtures\TestBundle\Entity;
 
 use ApiPlatform\Core\Annotation\ApiResource;
+use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 
@@ -47,6 +48,17 @@ class PatchDummyRelation
      */
     protected $related;
 
+    /**
+     * @ORM\OneToMany(targetEntity="RelatedDummy", mappedBy="relatedPatchDummy")
+     * @Groups({"chicago"})
+     */
+    protected $relatedDummies;
+
+    public function __construct()
+    {
+        $this->relatedDummies = new ArrayCollection();
+    }
+
     public function getRelated()
     {
         return $this->related;
@@ -56,4 +68,29 @@ public function setRelated(RelatedDummy $relatedDummy)
     {
         $this->related = $relatedDummy;
     }
+
+    /**
+     * @return Collection|RelatedDummy[]
+     */
+    public function getRelatedDummies(): Collection
+    {
+        return $this->relatedDummies;
+    }
+
+    public function addRelatedDummy(RelatedDummy $relatedDummy): self
+    {
+        if (!$this->relatedDummies->contains($relatedDummy)) {
+            $this->relatedDummies[] = $relatedDummy;
+            $relatedDummy->relatedPatchDummy = $this;
+        }
+
+        return $this;
+    }
+
+    public function removeRelatedDummy(RelatedDummy $relatedDummy): self
+    {
+        $this->relatedDummies->removeElement($relatedDummy);
+
+        return $this;
+    }
 }
diff --git a/tests/Fixtures/TestBundle/Entity/RelatedDummy.php b/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
index 73844a82116..f8830833bf0 100644
--- a/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
+++ b/tests/Fixtures/TestBundle/Entity/RelatedDummy.php
@@ -78,6 +78,11 @@ class RelatedDummy extends ParentDummy
      */
     public $relatedToDummyFriend;
 
+    /**
+     * @ORM\ManyToOne(targetEntity="PatchDummyRelation", inversedBy="relatedDummies")
+     */
+    public $relatedPatchDummy;
+
     /**
      * @var bool A dummy bool
      *