diff --git a/packages/server/src/api/routes/query.js b/packages/server/src/api/routes/query.js
index 4266cf6bdc..55223e4e9e 100644
--- a/packages/server/src/api/routes/query.js
+++ b/packages/server/src/api/routes/query.js
@@ -27,7 +27,7 @@ function generateQueryValidation() {
     readable: Joi.boolean(),
     parameters: Joi.array().items(Joi.object({
       name: Joi.string(),
-      default: Joi.string()
+      default: Joi.string().allow(""),
     })),
     queryVerb: Joi.string().allow().required(),
     schema: Joi.object({}).required().unknown(true)