diff --git a/src/Bundle/ChillActivityBundle/Entity/Activity.php b/src/Bundle/ChillActivityBundle/Entity/Activity.php
index 6b69bdf8e..53fd679e5 100644
--- a/src/Bundle/ChillActivityBundle/Entity/Activity.php
+++ b/src/Bundle/ChillActivityBundle/Entity/Activity.php
@@ -400,9 +400,11 @@ class Activity implements HasCenterInterface, HasScopeInterface
     /**
      * Add a person to the person list
      */
-    public function addPerson(Person $person): self
+    public function addPerson(?Person $person): self
     {
-        $this->persons[] = $person;
+        if (null !== $person) {
+            $this->persons[] = $person;
+        }
 
         return $this;
     }