diff --git a/docs/models.yml b/docs/models.yml
index 437a184f3..8fbf34554 100644
--- a/docs/models.yml
+++ b/docs/models.yml
@@ -1221,7 +1221,6 @@ motion_category:
     required: true
   prefix:
     type: string
-    required: true
   weight:
     type: number
     default: 10000