diff --git a/src/Symfony/Component/Form/ChoiceList/Factory/DefaultChoiceListFactory.php b/src/Symfony/Component/Form/ChoiceList/Factory/DefaultChoiceListFactory.php
index 5383f2a78393c..15b1661d909af 100644
--- a/src/Symfony/Component/Form/ChoiceList/Factory/DefaultChoiceListFactory.php
+++ b/src/Symfony/Component/Form/ChoiceList/Factory/DefaultChoiceListFactory.php
@@ -63,9 +63,11 @@ public function createView(ChoiceListInterface $list, $preferredChoices = null,
             $index = 0;
         }
 
-        // If $groupBy is a callable, choices are added to the group with the
-        // name returned by the callable. If the callable returns null, the
-        // choice is not added to any group
+        // If $groupBy is a callable returning a string
+        // choices are added to the group with the name returned by the callable.
+        // If $groupBy is a callable returning an array
+        // choices are added to the groups with names returned by the callable
+        // If the callable returns null, the choice is not added to any group
         if (\is_callable($groupBy)) {
             foreach ($choices as $value => $choice) {
                 self::addChoiceViewGroupedBy(
@@ -200,9 +202,9 @@ private static function addChoiceViewsGroupedBy($groupBy, $label, $choices, $key
 
     private static function addChoiceViewGroupedBy($groupBy, $choice, $value, $label, $keys, &$index, $attr, $isPreferred, &$preferredViews, &$otherViews)
     {
-        $groupLabel = $groupBy($choice, $keys[$value], $value);
+        $groupLabels = $groupBy($choice, $keys[$value], $value);
 
-        if (null === $groupLabel) {
+        if (null === $groupLabels) {
             // If the callable returns null, don't group the choice
             self::addChoiceView(
                 $choice,
@@ -219,25 +221,27 @@ private static function addChoiceViewGroupedBy($groupBy, $choice, $value, $label
             return;
         }
 
-        $groupLabel = (string) $groupLabel;
+        $groupLabels = \is_array($groupLabels) ? \array_map('strval', $groupLabels) : [(string) $groupLabels];
 
-        // Initialize the group views if necessary. Unnecessarily built group
-        // views will be cleaned up at the end of createView()
-        if (!isset($preferredViews[$groupLabel])) {
-            $preferredViews[$groupLabel] = new ChoiceGroupView($groupLabel);
-            $otherViews[$groupLabel] = new ChoiceGroupView($groupLabel);
-        }
+        foreach ($groupLabels as $groupLabel) {
+            // Initialize the group views if necessary. Unnecessarily built group
+            // views will be cleaned up at the end of createView()
+            if (!isset($preferredViews[$groupLabel])) {
+                $preferredViews[$groupLabel] = new ChoiceGroupView($groupLabel);
+                $otherViews[$groupLabel] = new ChoiceGroupView($groupLabel);
+            }
 
-        self::addChoiceView(
-            $choice,
-            $value,
-            $label,
-            $keys,
-            $index,
-            $attr,
-            $isPreferred,
-            $preferredViews[$groupLabel]->choices,
-            $otherViews[$groupLabel]->choices
-        );
+            self::addChoiceView(
+                $choice,
+                $value,
+                $label,
+                $keys,
+                $index,
+                $attr,
+                $isPreferred,
+                $preferredViews[$groupLabel]->choices,
+                $otherViews[$groupLabel]->choices
+            );
+        }
     }
 }
diff --git a/src/Symfony/Component/Form/Tests/ChoiceList/Factory/DefaultChoiceListFactoryTest.php b/src/Symfony/Component/Form/Tests/ChoiceList/Factory/DefaultChoiceListFactoryTest.php
index c520ab1a0de74..5e684687ecf57 100644
--- a/src/Symfony/Component/Form/Tests/ChoiceList/Factory/DefaultChoiceListFactoryTest.php
+++ b/src/Symfony/Component/Form/Tests/ChoiceList/Factory/DefaultChoiceListFactoryTest.php
@@ -77,6 +77,11 @@ public function getGroup($object)
         return $this->obj1 === $object || $this->obj2 === $object ? 'Group 1' : 'Group 2';
     }
 
+    public function getGroupArray($object)
+    {
+        return $this->obj1 === $object || $this->obj2 === $object ? ['Group 1', 'Group 2'] : ['Group 3'];
+    }
+
     public function getGroupAsObject($object)
     {
         return $this->obj1 === $object || $this->obj2 === $object
@@ -462,6 +467,19 @@ public function testCreateViewFlatGroupByAsCallable()
         $this->assertGroupedView($view);
     }
 
+    public function testCreateViewFlatGroupByAsCallableReturnsArray()
+    {
+        $view = $this->factory->createView(
+            $this->list,
+            [],
+            null, // label
+            null, // index
+            [$this, 'getGroupArray']
+        );
+
+        $this->assertGroupedViewWithChoiceDuplication($view);
+    }
+
     public function testCreateViewFlatGroupByObjectThatCanBeCastToString()
     {
         $view = $this->factory->createView(
@@ -773,6 +791,26 @@ private function assertGroupedView($view)
                 ]
         ), $view);
     }
+
+    private function assertGroupedViewWithChoiceDuplication($view)
+    {
+        $this->assertEquals(new ChoiceListView(
+            [
+                'Group 1' => new ChoiceGroupView(
+                    'Group 1',
+                    [0 => new ChoiceView($this->obj1, '0', 'A'), 2 => new ChoiceView($this->obj2, '1', 'B')]
+                ),
+                'Group 2' => new ChoiceGroupView(
+                    'Group 2',
+                    [1 => new ChoiceView($this->obj1, '0', 'A'), 3 => new ChoiceView($this->obj2, '1', 'B')]
+                ),
+                'Group 3' => new ChoiceGroupView(
+                    'Group 3',
+                    [4 => new ChoiceView($this->obj3, '2', 'C'), 5 => new ChoiceView($this->obj4, '3', 'D')]
+                ),
+            ], []
+        ), $view);
+    }
 }
 
 class DefaultChoiceListFactoryTest_Castable