diff --git a/Framework/Geometry/inc/MantidGeometry/Crystal/ReducedCell.h b/Framework/Geometry/inc/MantidGeometry/Crystal/ReducedCell.h
index e547ed6c6d0136b195d9068b0131cb3e4dd4bd7a..d7f8fa7beaee5f3992826d14b6e083e00fdf6d0b 100644
--- a/Framework/Geometry/inc/MantidGeometry/Crystal/ReducedCell.h
+++ b/Framework/Geometry/inc/MantidGeometry/Crystal/ReducedCell.h
@@ -3,6 +3,7 @@
 
 #include "MantidGeometry/DllConfig.h"
 #include "MantidKernel/Matrix.h"
+#include <string>
 
 namespace Mantid {
 namespace Geometry {
diff --git a/Framework/Kernel/inc/MantidKernel/Matrix.h b/Framework/Kernel/inc/MantidKernel/Matrix.h
index 17d763e0c241ae321ce2065de994f809d21cd222..f5625946f5a5834614b94155c7913fb510f33ac2 100644
--- a/Framework/Kernel/inc/MantidKernel/Matrix.h
+++ b/Framework/Kernel/inc/MantidKernel/Matrix.h
@@ -4,7 +4,7 @@
 #include "MantidKernel/DllConfig.h"
 #include <vector>
 #include <cfloat>
-#include <ostream>
+#include <iosfwd>
 
 namespace Mantid {