diff --git a/include/json/value.h b/include/json/value.h
index 26bb38b69..426b0f742 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -211,7 +211,7 @@ class JSON_API Value {
     void swap(CZString& other);
 
     struct StringStorage {
-      DuplicationPolicy policy_: 2;
+      unsigned policy_: 2;
       unsigned length_: 30; // 1GB max
     };