diff --git a/src/Value.cpp b/src/Value.cpp
index 4ebb5dd64d..aa5708b000 100644
--- a/src/Value.cpp
+++ b/src/Value.cpp
@@ -22,6 +22,16 @@ StringValue::StringValue(llvm::StringRef val) {
   str[len] = '\0';
 }
 
+StringValue& StringValue::operator=(llvm::StringRef val) {
+  NT_DisposeString(this);
+  str = nullptr;
+  len = val.size();
+  str = static_cast<char*>(std::malloc(len+1));
+  std::memcpy(str, val.data(), len);
+  str[len] = '\0';
+  return *this;
+}
+
 void Value::SetBooleanArray(llvm::ArrayRef<int> value) {
   // handle type change
   if (NT_Value::type != NT_BOOLEAN_ARRAY) {
diff --git a/src/Value.h b/src/Value.h
index d028110e32..5f116b10b8 100644
--- a/src/Value.h
+++ b/src/Value.h
@@ -35,7 +35,7 @@ class StringValue : private NT_String {
   friend class WireDecoder;
  public:
   StringValue() { NT_InitString(this); }
-  explicit StringValue(llvm::StringRef val);
+  StringValue(llvm::StringRef val);
   ~StringValue() { NT_DisposeString(this); }
 
   operator llvm::StringRef() const { return llvm::StringRef(str, len); }
@@ -60,6 +60,8 @@ class StringValue : private NT_String {
     }
     return *this;
   }
+
+  StringValue& operator=(llvm::StringRef val);
 };
 
 inline bool operator==(const StringValue& lhs, const StringValue& rhs) {