diff --git a/lib/index.js b/lib/index.js
index 79ac789..1098c80 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -2,15 +2,16 @@
 
 import readCache from './read-cache'
 import serialize from './serialize'
+import memoryStore from './memory'
 
 function cache (config = {}) {
-  if (!config.store) {
+  const store = config.store || memoryStore
+  const key = config.key || cache.key
+
+  if (!store) {
     throw new Error('Cache middleware need to be provided a store.')
   }
 
-  const store = config.store
-  const key = config.key || cache.key
-
   config.maxAge = config.maxAge || 0
   config.readCache = config.readCache || readCache
   config.serialize = config.serialize || serialize