lib/PublicInbox/HTTPD/Async.pm | 1 +

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index a936d9b5a0c6fc5e3988c88085437a1322b13333..880cf021cef763a97ea9add08cea295d4c9789fa 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -41,6 +41,7 @@ 	$self->{cb} = sub {
 		my $r = sysread($self->{sock}, $$bref, 8192);
 		if ($r) {
 			$fh->write($$bref);
+			return if $io->{closed};
 			if ($io->{write_buf_size}) {
 				$self->watch_read(0);
 				$io->write($restart_read); # D::S::write