diff --git a/base/inc/ImageIO.h b/base/inc/ImageIO.h
index f93866c..046dacb 100644
--- a/base/inc/ImageIO.h
+++ b/base/inc/ImageIO.h
@@ -17,6 +17,7 @@
 #define Force_ImageIO_H

 #include <map>
+#include <string>

 #include "Defines.h"