lib/PublicInbox/HTTPD/Async.pm | 8 +++++---
 lib/PublicInbox/Qspawn.pm      | 4 ++--

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index e03daafac8d1a7994042fa52e94e4eac60f7ac4c..7bbab1e1cd65c22d2a895f5a99b5924fa172afd5 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -14,7 +14,7 @@ # cb: initial read callback
 # arg: arg for {cb}
 # end_obj: CODE or object which responds to ->event_step when ->close is called
 package PublicInbox::HTTPD::Async;
-use strict;
+use v5.12;
 use parent qw(PublicInbox::DS);
 use Errno qw(EAGAIN);
 use PublicInbox::Syscall qw(EPOLLIN);
@@ -44,9 +44,9 @@ }
 
 sub event_step {
 	my ($self) = @_;
-	if (my $cb = delete $self->{cb}) {
+	if (defined $self->{cb}) {
 		# this may call async_pass when headers are done
-		$cb->(my $refcnt_guard = delete $self->{arg});
+		$self->{cb}->($self->{arg});
 	} elsif (my $sock = $self->{sock}) {
 		# $http may be undef if discarding body output from cgit on 404
 		my $http = $self->{http} or return $self->close;
@@ -76,6 +76,7 @@ # $ofh is typically PublicInbox::HTTP::{Chunked,Identity}, but
 # may be PublicInbox::GzipFilter or $PublicInbox::Qspawn::qx_fh
 sub async_pass {
 	my ($self, $http, $ofh, $bref) = @_;
+	delete @$self{qw(cb arg)};
 	# In case the client HTTP connection ($http) dies, it
 	# will automatically close this ($self) object.
 	$http->{forward} = $self;
@@ -94,6 +95,7 @@ # may be called as $forward->close in PublicInbox::HTTP or EOF (event_step)
 sub close {
 	my $self = $_[0];
 	$self->SUPER::close; # DS::close
+	delete @$self{qw(cb arg)};
 
 	# we defer this to the next timer loop since close is deferred
 	if (my $end_obj = delete $self->{end_obj}) {
diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index f8cbffcb359b74629a888119bcbba4237335d0ad..7984e35a80510ffdf09cbb7f5e325ecd9eb764a0 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -134,7 +134,7 @@ 		push @{$limiter->{run_queue}}, [ $self, $start_cb ];
 	}
 }
 
-sub psgi_qx_init_cb {
+sub psgi_qx_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
 	my $async = delete $self->{async}; # PublicInbox::HTTPD::Async
 	my ($r, $buf);
@@ -223,7 +223,7 @@ 	delete $self->{parse_hdr}; # done parsing headers
 	$ret;
 }
 
-sub psgi_return_init_cb {
+sub psgi_return_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
 	my ($self) = @_;
 	my $r = rd_hdr($self) or return;
 	my $env = $self->{psgi_env};