diff --git a/src/Symfony/Bridge/Doctrine/PropertyInfo/DoctrineExtractor.php b/src/Symfony/Bridge/Doctrine/PropertyInfo/DoctrineExtractor.php
index 0cfdc8768c..651ff3e96c 100644
--- a/src/Symfony/Bridge/Doctrine/PropertyInfo/DoctrineExtractor.php
+++ b/src/Symfony/Bridge/Doctrine/PropertyInfo/DoctrineExtractor.php
@@ -110,10 +110,24 @@ class DoctrineExtractor implements PropertyListExtractorInterface, PropertyTypeE
                 $associationMapping = $metadata->getAssociationMapping($property);
 
                 if (isset($associationMapping['indexBy'])) {
-                    $indexColumn = $associationMapping['indexBy'];
                     /** @var ClassMetadataInfo $subMetadata */
                     $subMetadata = $this->classMetadataFactory->getMetadataFor($associationMapping['targetEntity']);
-                    $typeOfField = $subMetadata->getTypeOfField($subMetadata->getFieldForColumn($indexColumn));
+
+                    // Check if indexBy value is a property
+                    $fieldName = $associationMapping['indexBy'];
+                    if (null === ($typeOfField = $subMetadata->getTypeOfField($fieldName))) {
+                        $fieldName = $subMetadata->getFieldForColumn($associationMapping['indexBy']);
+                        //Not a property, maybe a column name?
+                        if (null === ($typeOfField = $subMetadata->getTypeOfField($fieldName))) {
+                            //Maybe the column name is the association join column?
+                            $associationMapping = $subMetadata->getAssociationMapping($fieldName);
+
+                            /** @var ClassMetadataInfo $subMetadata */
+                            $indexProperty = $subMetadata->getSingleAssociationReferencedJoinColumnName($fieldName);
+                            $subMetadata = $this->classMetadataFactory->getMetadataFor($associationMapping['targetEntity']);
+                            $typeOfField = $subMetadata->getTypeOfField($indexProperty);
+                        }
+                    }
 
                     if (!$collectionKeyType = $this->getPhpType($typeOfField)) {
                         return null;
diff --git a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/DoctrineExtractorTest.php b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/DoctrineExtractorTest.php
index b9abd03347..845a0612b8 100644
--- a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/DoctrineExtractorTest.php
+++ b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/DoctrineExtractorTest.php
@@ -72,8 +72,10 @@ class DoctrineExtractorTest extends TestCase
         $expected = array_merge($expected, [
             'foo',
             'bar',
+            'indexedRguid',
             'indexedBar',
             'indexedFoo',
+            'indexedBaz',
             'indexedByDt',
             'indexedByCustomType',
         ]);
@@ -151,6 +153,14 @@ class DoctrineExtractorTest extends TestCase
                 new Type(Type::BUILTIN_TYPE_INT),
                 new Type(Type::BUILTIN_TYPE_OBJECT, false, 'Symfony\Bridge\Doctrine\Tests\PropertyInfo\Fixtures\DoctrineRelation')
             )]],
+            ['indexedRguid', [new Type(
+                Type::BUILTIN_TYPE_OBJECT,
+                false,
+                'Doctrine\Common\Collections\Collection',
+                true,
+                new Type(Type::BUILTIN_TYPE_STRING),
+                new Type(Type::BUILTIN_TYPE_OBJECT, false, 'Symfony\Bridge\Doctrine\Tests\PropertyInfo\Fixtures\DoctrineRelation')
+            )]],
             ['indexedBar', [new Type(
                 Type::BUILTIN_TYPE_OBJECT,
                 false,
@@ -167,6 +177,14 @@ class DoctrineExtractorTest extends TestCase
                 new Type(Type::BUILTIN_TYPE_STRING),
                 new Type(Type::BUILTIN_TYPE_OBJECT, false, 'Symfony\Bridge\Doctrine\Tests\PropertyInfo\Fixtures\DoctrineRelation')
             )]],
+            ['indexedBaz', [new Type(
+                Type::BUILTIN_TYPE_OBJECT,
+                false,
+                Collection::class,
+                true,
+                new Type(Type::BUILTIN_TYPE_INT),
+                new Type(Type::BUILTIN_TYPE_OBJECT, false, DoctrineRelation::class)
+            )]],
             ['simpleArray', [new Type(Type::BUILTIN_TYPE_ARRAY, false, null, true, new Type(Type::BUILTIN_TYPE_INT), new Type(Type::BUILTIN_TYPE_STRING))]],
             ['customFoo', null],
             ['notMapped', null],
diff --git a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineDummy.php b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineDummy.php
index 568efce33d..46e5b23414 100644
--- a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineDummy.php
+++ b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineDummy.php
@@ -41,6 +41,11 @@ class DoctrineDummy
      */
     public $bar;
 
+    /**
+     * @ManyToMany(targetEntity="DoctrineRelation", indexBy="rguid")
+     */
+    protected $indexedRguid;
+
     /**
      * @ManyToMany(targetEntity="DoctrineRelation", indexBy="rguid_column")
      */
@@ -51,6 +56,11 @@ class DoctrineDummy
      */
     protected $indexedFoo;
 
+    /**
+     * @OneToMany(targetEntity="DoctrineRelation", mappedBy="baz", indexBy="baz_id")
+     */
+    protected $indexedBaz;
+
     /**
      * @Column(type="guid")
      */
diff --git a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineRelation.php b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineRelation.php
index e480ca9d77..b40c0883e1 100644
--- a/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineRelation.php
+++ b/src/Symfony/Bridge/Doctrine/Tests/PropertyInfo/Fixtures/DoctrineRelation.php
@@ -40,6 +40,11 @@ class DoctrineRelation
      */
     protected $foo;
 
+    /**
+     * @ManyToOne(targetEntity="DoctrineDummy")
+     */
+    protected $baz;
+
     /**
      * @Column(type="datetime")
      */