diff --git a/src/lib/eo/eo_base.eo b/src/lib/eo/eo_base.eo
index ad6cd68bee..9043cf9159 100644
--- a/src/lib/eo/eo_base.eo
+++ b/src/lib/eo/eo_base.eo
@@ -62,7 +62,7 @@ abstract Eo.Base ()
             [[Get the parent of an object]]
          }
          values {
-            parent: Eo.Base*; [[the new parent]]
+            parent: Eo.Base * @nullable; [[the new parent]]
          }
       }
       @property event_global_freeze_count @class {