diff --git a/lib/pleroma/web/api_spec/operations/instance_operation.ex b/lib/pleroma/web/api_spec/operations/instance_operation.ex
index 9d189d029..d5c335d0c 100644
--- a/lib/pleroma/web/api_spec/operations/instance_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/instance_operation.ex
@@ -125,7 +125,12 @@ defmodule Pleroma.Web.ApiSpec.InstanceOperation do
         },
         avatar_upload_limit: %Schema{type: :integer, description: "The title of the website"},
         background_upload_limit: %Schema{type: :integer, description: "The title of the website"},
-        banner_upload_limit: %Schema{type: :integer, description: "The title of the website"}
+        banner_upload_limit: %Schema{type: :integer, description: "The title of the website"},
+        background_image: %Schema{
+          type: :string,
+          format: :uri,
+          description: "The background image for the website"
+        }
       },
       example: %{
         "avatar_upload_limit" => 2_000_000,