diff --git a/src/Bundle/ChillMainBundle/Form/Type/DataTransformer/EntityToJsonTransformer.php b/src/Bundle/ChillMainBundle/Form/Type/DataTransformer/EntityToJsonTransformer.php
index c6839efa8..21f976a0f 100644
--- a/src/Bundle/ChillMainBundle/Form/Type/DataTransformer/EntityToJsonTransformer.php
+++ b/src/Bundle/ChillMainBundle/Form/Type/DataTransformer/EntityToJsonTransformer.php
@@ -28,10 +28,14 @@ class EntityToJsonTransformer implements DataTransformerInterface
 
     public function reverseTransform($value)
     {
-        if ('' === $value) {
+        if (false === $this->multiple && '' === $value) {
             return null;
         }
 
+        if ($this->multiple && [] === $value) {
+            return [];
+        }
+
         $denormalized = json_decode((string) $value, true, 512, JSON_THROW_ON_ERROR);
 
         if ($this->multiple) {
diff --git a/src/Bundle/ChillMainBundle/Form/WorkflowStepType.php b/src/Bundle/ChillMainBundle/Form/WorkflowStepType.php
index b786a450d..1984437f8 100644
--- a/src/Bundle/ChillMainBundle/Form/WorkflowStepType.php
+++ b/src/Bundle/ChillMainBundle/Form/WorkflowStepType.php
@@ -188,6 +188,7 @@ class WorkflowStepType extends AbstractType
                 'label' => 'workflow.transition_destinee_third_party',
                 'help' => 'workflow.transition_destinee_third_party_help',
                 'multiple' => true,
+                'empty_data' => [],
             ]);
 
         $builder