diff --git a/src/ast.hpp b/src/ast.hpp
index f55ab39..93127d5 100644
--- a/src/ast.hpp
+++ b/src/ast.hpp
@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "CTree.hpp"
+#include "utils.hpp"
 namespace x3 = boost::spirit::x3;
 namespace ascii = boost::spirit::x3::ascii;