diff --git a/docs/models.yml b/docs/models.yml
index 527ecf813..f1ba54b97 100644
--- a/docs/models.yml
+++ b/docs/models.yml
@@ -1246,7 +1246,6 @@ motion_category:
     required: true
   prefix:
     type: string
-    required: true
   weight:
     type: number
     default: 10000