diff --git a/include/sqlpp11/schema.h b/include/sqlpp11/schema.h
index 5163436c..4730817b 100644
--- a/include/sqlpp11/schema.h
+++ b/include/sqlpp11/schema.h
@@ -27,6 +27,8 @@
 #ifndef SQLPP_SCHEMA_H
 #define SQLPP_SCHEMA_H
 
+#include <string>
+
 #include <sqlpp11/type_traits.h>
 #include <sqlpp11/serializer.h>