diff --git a/Slang/builtin.h b/Slang/builtin.h
index 0aa95ef..9a4574f 100644
--- a/Slang/builtin.h
+++ b/Slang/builtin.h
@@ -14,6 +14,7 @@
 #include "anyops.h"
 
 using namespace std;
+using namespace boost;
 
 vector<string> types = { "int", "float", "string", "bool", "void", "null" };