diff --git a/Buildscr b/Buildscr
index 9ea88a84..a476ff75 100644
--- a/Buildscr
+++ b/Buildscr
@@ -160,8 +160,10 @@ delegate windows
   # Build the original binaries.
   in putty/windows with visualstudio do/win mkdir buildold && nmake -f Makefile.vc BUILDDIR=buildold\ $(Makeargs) all cleantestprogs
 
-  # Build the VS2015 binaries.
-  in putty/windows with visualstudio2015_32bit do/win mkdir build32 && nmake -f Makefile.vc BUILDDIR=build32\ $(Makeargs) all cleantestprogs
+  # Build the VS2015 binaries. For the 32-bit ones, we set a subsystem
+  # version of 5.01, which allows the resulting files to still run on
+  # Windows XP.
+  in putty/windows with visualstudio2015_32bit do/win mkdir build32 && nmake -f Makefile.vc BUILDDIR=build32\ SUBSYSVER=,5.01 $(Makeargs) all cleantestprogs
   in putty/windows with visualstudio2015_64bit do/win mkdir build64 && nmake -f Makefile.vc BUILDDIR=build64\ $(Makeargs) all cleantestprogs
 
   # Code-sign the binaries, if the local bob config provides a script
diff --git a/mkfiles.pl b/mkfiles.pl
index 3e42c734..4a2b3b4d 100755
--- a/mkfiles.pl
+++ b/mkfiles.pl
@@ -676,7 +676,7 @@ if (defined $makefiles{'vc'}) {
 	    print "$objlines[$i]\n";
 	}
 	print "<<\n";
-	print "\tlink \$(LFLAGS) \$(XLFLAGS) -out:\$(BUILDDIR)$prog.exe -map:\$(BUILDDIR)$prog.map -nologo -subsystem:$subsys \@$inlinefilename\n\n";
+	print "\tlink \$(LFLAGS) \$(XLFLAGS) -out:\$(BUILDDIR)$prog.exe -map:\$(BUILDDIR)$prog.map -nologo -subsystem:$subsys\$(SUBSYSVER) \@$inlinefilename\n\n";
     }
     foreach $d (&deps("\$(BUILDDIR)X.obj", "\$(BUILDDIR)X.res", $dirpfx, "\\", "vc")) {
         $extradeps = $forceobj{$d->{obj_orig}} ? ["*.c","*.h","*.rc"] : [];