diff --git a/src/policy_cache.hpp b/src/policy_cache.hpp
index b580a8a9..706b7cb6 100644
--- a/src/policy_cache.hpp
+++ b/src/policy_cache.hpp
@@ -49,5 +49,5 @@ public:
 
 private:
   pthread_mutex_t             _lock;
-  std::unordered_map<std::string,Value> _cache;
+  std::unordered_map<std::string,std::string> _cache;
 };