diff --git a/api.yaml b/api.yaml
index 4630394..0c130cf 100644
--- a/api.yaml
+++ b/api.yaml
@@ -325,7 +325,8 @@ paths:
                   type: string
                   description: Name of the asset
                 data:
-                  description: The asset itself
+                  type: string
+                  description: The asset itself. Must be encoded as base64
       security:
         - cookie: []
       responses: