diff --git a/winsup/ccwrap b/winsup/ccwrap
index 7580e7a3b..2f1fd3a98 100755
--- a/winsup/ccwrap
+++ b/winsup/ccwrap
@@ -12,6 +12,11 @@ if ($ARGV[0] ne '++') {
     $cxx = 1;
 }
 die "$0: $ccorcxx environment variable does not exist\n" unless exists $ENV{$ccorcxx};
+if (`uname -o` =~ /cygwin/i) {
+    $ENV{'LANG'} = 'C.UTF-8';
+} else {
+    $ENV{'LANG'} = 'C';
+}
 my @compiler = split ' ', $ENV{$ccorcxx};
 if ("@ARGV" !~ / -nostdinc/o) {
     my $fd;