--- a/ext/v8/context.cc
+++ b/ext/v8/context.cc
@@ -78,7 +78,7 @@
 }
 
 VALUE Context::SetData(VALUE self, VALUE data) {
-  Void(Context(self)->SetData(String(data)));
+  Void(Context(self)->SetData(Value(data)));
 }
 
 VALUE Context::GetData(VALUE self) {