Another shot at #411
diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp
index e6eb345..17a8455 100644
--- a/src/lib_json/json_value.cpp
+++ b/src/lib_json/json_value.cpp
@@ -234,7 +234,7 @@
storage_.policy_ = static_cast<unsigned>(other.cstr_
? (static_cast<DuplicationPolicy>(other.storage_.policy_) == noDuplication
? noDuplication : duplicate)
- : static_cast<DuplicationPolicy>(other.storage_.policy_));
+ : static_cast<DuplicationPolicy>(other.storage_.policy_)) & 3U;
storage_.length_ = other.storage_.length_;
}