-open OLDOUT, '>&STDOUT' or die "dup STDOUT: $!";
-open OLDERR, '>&STDERR' or die "dup STDERR: $!";
-OLDOUT->autoflush(1);
-OLDERR->autoflush(1);
+open my $OLDOUT, '>&STDOUT' or die "dup STDOUT: $!";
+open my $OLDERR, '>&STDERR' or die "dup STDERR: $!";
+$OLDOUT->autoflush(1);
+$OLDERR->autoflush(1);