diff --git a/src/hb-uniscribe.cc b/src/hb-uniscribe.cc
index b71b00a2c..e5b98a825 100644
--- a/src/hb-uniscribe.cc
+++ b/src/hb-uniscribe.cc
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#define _WIN32_WINNT 0x0500
+#define _WIN32_WINNT 0x0600
 
 #include "hb-private.hh"
 
diff --git a/src/hb-uniscribe.h b/src/hb-uniscribe.h
index 216610ebd..bb99f3987 100644
--- a/src/hb-uniscribe.h
+++ b/src/hb-uniscribe.h
@@ -29,7 +29,7 @@
 
 #include "hb.h"
 
-#define _WIN32_WINNT 0x0500
+#define _WIN32_WINNT 0x0600
 #include <windows.h>
 
 HB_BEGIN_DECLS