diff --git a/lib/hydrate.js b/lib/hydrate.js
index <HASH>..<HASH> 100644
--- a/lib/hydrate.js
+++ b/lib/hydrate.js
@@ -13,9 +13,10 @@ value should have the following format
   }
 }
 */
-  const xhr = value.body || {}
-  const headers = value.headers || {}
 export default function hydrate (value) {
+  const data = JSON.parse(value)
+  const xhr = data.body || {}
+  const headers = data.headers || {}
 
   xhr.getAllResponseHeaders = function () {
     return headers
feat(hydrate): parse JSON-based cache value