--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -128,17 +128,17 @@ else
 fi
 
 MOZ_TOOL_VARIABLES
 
 dnl Special win32 checks
 dnl ========================================================
 
 # Target the Windows 8.1 SDK by default
-WINVER=502
+WINVER=601
 
 case "$target" in
 *-mingw*)
     if test "$GCC" != "yes"; then
         # Check to see if we are really running in a msvc environemnt
         _WIN32_MSVC=1
 
         # Make sure compilers are valid

--- a/old-configure.in
+++ b/old-configure.in
@@ -198,17 +198,17 @@ if test -n "$MOZ_WINCONSOLE"; then
 fi
 
 MOZ_TOOL_VARIABLES
 
 dnl ========================================================
 dnl Special win32 checks
 dnl ========================================================
 
-WINVER=502
+WINVER=601
 
 case "$target" in
 *-mingw*)
     if test "$GCC" != "yes"; then
         # Check to see if we are really running in a msvc environemnt
         _WIN32_MSVC=1
         AC_CHECK_PROGS(MIDL, midl)