Taken from http://rt.openssl.org/Ticket/Display.html?id=2440

--- crypto/sha/asm/sha512-x86_64.pl	2008-12-19 11:17:28.000000000 +0000
+++ crypto/sha/asm/sha512-x86_64.pl	2011-01-15 23:33:13.000000000 +0000
@@ -51,6 +51,7 @@
 ( $xlate="${dir}../../perlasm/x86_64-xlate.pl" and -f $xlate) or
 die "can't locate x86_64-xlate.pl";
 
+close STDOUT;
 open STDOUT,"| $^X $xlate $flavour $output";
 
 if ($output =~ /512/) {