diff --git a/Framework/API/inc/MantidAPI/ITransformScale.h b/Framework/API/inc/MantidAPI/ITransformScale.h
index d13af449f046120f40869cb0f8d2208312c60088..18832392062ceba43c5749aed0ea7201681dfaab 100644
--- a/Framework/API/inc/MantidAPI/ITransformScale.h
+++ b/Framework/API/inc/MantidAPI/ITransformScale.h
@@ -8,6 +8,7 @@
 #include <boost/shared_ptr.hpp>
 #endif
 
+#include <string>
 #include <vector>
 
 #include "MantidAPI/DllConfig.h"