diff --git a/notebook/services/api/api.yaml b/notebook/services/api/api.yaml
index 4cf8f9c9d..dca988b59 100644
--- a/notebook/services/api/api.yaml
+++ b/notebook/services/api/api.yaml
@@ -816,8 +816,7 @@ definitions:
         format: dateTime
       size:
         type: integer
-        description: "The size of the file or directory."
-        format: bytes
+        description: "The size of the file or notebook in bytes. If no size is provided, defaults to None."
       mimetype:
         type: string
         description: "The mimetype of a file.  If content is not null, and type is 'file', this will contain the mimetype of the file, otherwise this will be null."