diff --git a/packages/jspsych/src/modules/plugin-api/MediaAPI.ts b/packages/jspsych/src/modules/plugin-api/MediaAPI.ts
index 5e5ecb80..6dabb447 100644
--- a/packages/jspsych/src/modules/plugin-api/MediaAPI.ts
+++ b/packages/jspsych/src/modules/plugin-api/MediaAPI.ts
@@ -62,7 +62,7 @@ export class MediaAPI {
     files,
     callback_complete = () => {},
     callback_load = (filepath: string) => {},
-    callback_error = (error: string) => {}
+    callback_error = (error) => {}
   ) {
     files = unique(files.flat());