diff --git a/trunk/paradiseo-moeo/tutorial/Lesson1/src/flowshop/FlowShopBenchmarkParser.h b/trunk/paradiseo-moeo/tutorial/Lesson1/src/flowshop/FlowShopBenchmarkParser.h
index 3e1165d98..3532309e5 100644
--- a/trunk/paradiseo-moeo/tutorial/Lesson1/src/flowshop/FlowShopBenchmarkParser.h
+++ b/trunk/paradiseo-moeo/tutorial/Lesson1/src/flowshop/FlowShopBenchmarkParser.h
@@ -14,6 +14,7 @@
 #define FLOWSHOPBENCHMARKPARSER_H_
 
 #include <fstream>
+#include <string>
 #include <vector>
 
 /**