diff --git a/internal.lua b/internal.lua
index f7c074e..6a4afc1 100644
--- a/internal.lua
+++ b/internal.lua
@@ -139,6 +139,9 @@ local function load_images_of_movie(movie_id)
     local movie = get_movie(movie_id)
     local loaded_count = 0
     local movie_files = movie.files or {}
+
+    if type(movie_files) ~= "table" then return 0, "no files" end
+
     for _, file in ipairs(movie_files) do
         local path = path_of_image(movie_id, file)
         local success = load_image(path)