diff --git a/xs/src/slic3r/Utils/ASCIIFolding.cpp b/xs/src/slic3r/Utils/ASCIIFolding.cpp
index 53b860d65..c61fe2902 100644
--- a/xs/src/slic3r/Utils/ASCIIFolding.cpp
+++ b/xs/src/slic3r/Utils/ASCIIFolding.cpp
@@ -1,6 +1,7 @@
 #include "ASCIIFolding.hpp"
 
 #include <stdio.h>
+#include <string.h>
 #include <locale>
 #include <boost/locale/encoding_utf.hpp>