diff --git a/client/src/utils/schemaUtils.ts b/client/src/utils/schemaUtils.ts
index ea92065..520b790 100644
--- a/client/src/utils/schemaUtils.ts
+++ b/client/src/utils/schemaUtils.ts
@@ -13,7 +13,7 @@ export function generateDefaultValue(schema: JsonSchemaType): JsonValue {
   if (!schema.required) {
     if (schema.type === "array") return [];
     if (schema.type === "object") return {};
-    return null;
+    return undefined;
   }
 
   switch (schema.type) {