diff --git a/code/BoostWorkaround/boost/lexical_cast.hpp b/code/BoostWorkaround/boost/lexical_cast.hpp
index 3f055f35f..7724e4607 100644
--- a/code/BoostWorkaround/boost/lexical_cast.hpp
+++ b/code/BoostWorkaround/boost/lexical_cast.hpp
@@ -3,6 +3,8 @@
 #ifndef __AI_BOOST_WORKAROUND_LEXICAL_CAST
 #define __AI_BOOST_WORKAROUND_LEXICAL_CAST
 
+#include <sstream>
+
 namespace boost
 {