diff --git a/backend/middlewares/api-utils.js b/backend/middlewares/api-utils.js
index 6679a935c..f8455bf52 100644
--- a/backend/middlewares/api-utils.js
+++ b/backend/middlewares/api-utils.js
@@ -78,7 +78,7 @@ function requestValidation(validationSchema) {
         throw new MonkeyError(
           500,
           validationErrorMessage ?? `Invalid request: ${errorMessage}`,
-          `${key}: ${req[key]}`
+          `${key}: ${JSON.stringify(req[key])}`
         );
       }
     });