diff --git a/index.js b/index.js
index cba7f28..d06bc76 100644
--- a/index.js
+++ b/index.js
@@ -120,7 +120,7 @@ const upload = multer({
     }
     if ((!allowedTypes.includes(file.mimetype) && file.mimetype != "application/octet-stream") || !allowedExtensions.includes(extname(file.originalname.toLowerCase()).substring(1))) {
       console.error('FileFilter: File is of an invalid type ', file)
-      cb("Invalid filetype: " + file, false)
+      cb("Invalid filetype: " + JSON.stringify(file), false)
       return
     }
     cb(null, true)