diff --git a/src/Symfony/Component/Form/CHANGELOG.md b/src/Symfony/Component/Form/CHANGELOG.md
index d5e8cc7004b70..25f47c7aa903e 100644
--- a/src/Symfony/Component/Form/CHANGELOG.md
+++ b/src/Symfony/Component/Form/CHANGELOG.md
@@ -39,6 +39,7 @@ CHANGELOG
  * deprecated calling `FormRenderer::searchAndRenderBlock` for fields which were already rendered
  * added a cause when a CSRF error has occurred
  * deprecated the `scale` option of the `IntegerType`
+ * findByCodes of `FormErrorIterator` is able to also filter causes that are string or objects that implement the `__toString` method
  * removed restriction on allowed HTTP methods
 
 4.1.0
diff --git a/src/Symfony/Component/Form/FormErrorIterator.php b/src/Symfony/Component/Form/FormErrorIterator.php
index 919b61596988c..10bcaf23ea01c 100644
--- a/src/Symfony/Component/Form/FormErrorIterator.php
+++ b/src/Symfony/Component/Form/FormErrorIterator.php
@@ -267,6 +267,16 @@ public function findByCodes($codes)
             $cause = $error->getCause();
             if ($cause instanceof ConstraintViolation && \in_array($cause->getCode(), $codes, true)) {
                 $errors[] = $error;
+                continue;
+            }
+
+            if (!is_scalar($cause) && !(\is_object($cause) && method_exists($cause, '__toString'))) {
+                continue;
+            }
+
+            $cause = (string) $cause;
+            if (\in_array($cause, $codes, true)) {
+                $errors[] = $error;
             }
         }
 
diff --git a/src/Symfony/Component/Form/Tests/FormErrorIteratorTest.php b/src/Symfony/Component/Form/Tests/FormErrorIteratorTest.php
index 04eddd1c32350..60398d8e9cefb 100644
--- a/src/Symfony/Component/Form/Tests/FormErrorIteratorTest.php
+++ b/src/Symfony/Component/Form/Tests/FormErrorIteratorTest.php
@@ -23,7 +23,7 @@ class FormErrorIteratorTest extends TestCase
     /**
      * @dataProvider findByCodesProvider
      */
-    public function testFindByCodes($code, $violationsCount)
+    public function testFindByCodesWhenAllCausesAreViolationConstraints($code, $violationsCount)
     {
         if (!class_exists(ConstraintViolation::class)) {
             $this->markTestSkipped('Validator component required.');
@@ -52,6 +52,43 @@ public function testFindByCodes($code, $violationsCount)
         $this->assertCount($violationsCount, $specificFormErrors);
     }
 
+    /**
+     * @dataProvider findByCodesProvider
+     */
+    public function testFindByCodesWhenAllCausesAreVariousObjectsOrSimpleStrings($code, $violationsCount)
+    {
+        if (!class_exists(ConstraintViolation::class)) {
+            $this->markTestSkipped('Validator component required.');
+        }
+
+        $formBuilder = new FormBuilder(
+            'form',
+            null,
+            new EventDispatcher(),
+            $this->getMockBuilder('Symfony\Component\Form\FormFactoryInterface')->getMock(),
+            array()
+        );
+
+        $form = $formBuilder->getForm();
+
+        $cause = new ConstraintViolation('Error 1!', null, array(), null, '', null, null, 'code1');
+        $form->addError(new FormError('Error 1!', null, array(), null, $cause));
+        $cause = new class() {
+            public function __toString()
+            {
+                return 'code1';
+            }
+        };
+
+        $form->addError(new FormError('Error 2!', null, array(), null, $cause));
+        $form->addError(new FormError('Error 3!', null, array(), null, 'code2'));
+        $formErrors = $form->getErrors();
+
+        $specificFormErrors = $formErrors->findByCodes($code);
+        $this->assertInstanceOf(FormErrorIterator::class, $specificFormErrors);
+        $this->assertCount($violationsCount, $specificFormErrors);
+    }
+
     public function findByCodesProvider()
     {
         return array(