diff --git a/docs/models.yml b/docs/models.yml
index 3fcd46c22..7323fe48c 100644
--- a/docs/models.yml
+++ b/docs/models.yml
@@ -91,7 +91,9 @@ organisation:
 
 user:
   id: number
-  username: string
+  username:
+    type: string
+    required: true
   title: string
   first_name: string
   last_name: string