diff --git a/src/Entity/Db/ProcessStep.php b/src/Entity/Db/ProcessStep.php
index e2640a5d1e5d5346b0ce8f1d5adb0dffb70f6b5b..d7aed7aa98e6a7b2875d8c8dbeb880c9bd0389c8 100644
--- a/src/Entity/Db/ProcessStep.php
+++ b/src/Entity/Db/ProcessStep.php
@@ -93,13 +93,13 @@ class ProcessStep
         return $this;
     }
 
-    public function setLabel($label) :ProcessStep {
+    public function setLabel(?string $label): ?string {
         $this->label = $label;
 
         return $this;
     }
 
-    public function getLabel() :string {
+    public function getLabel(): ?string {
         return $this->label;
     }