diff --git a/MMVII/include/MMVII_Stringifier.h b/MMVII/include/MMVII_Stringifier.h
index 9d243ab7cf..15139ffdf8 100755
--- a/MMVII/include/MMVII_Stringifier.h
+++ b/MMVII/include/MMVII_Stringifier.h
@@ -3,6 +3,7 @@
 
 #include "MMVII_memory.h"
 #include "MMVII_Ptxd.h"
+#include <sstream>
 
 namespace MMVII
 {