diff --git a/liberty/LibertyScanner.hh b/liberty/LibertyScanner.hh
index b32369cd..a649f514 100644
--- a/liberty/LibertyScanner.hh
+++ b/liberty/LibertyScanner.hh
@@ -24,6 +24,10 @@
 
 #pragma once
 
+#include <string>
+#include <istream>
+
+#include "LibertyParser.hh"
 #include "LibertyLocation.hh"
 #include "LibertyParse.hh"