1 files changed, 2 insertions, 3 deletions
diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 7454acbb..b39c8203 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -104,9 +104,8 @@ EOF
  sub in_reply_to {
          my ($hdr) = @_;
          my %mid = map { $_ => 1 } $hdr->header_raw('Message-ID');
-        my @refs = ($hdr->header_raw('References'),
-                        $hdr->header_raw('In-Reply-To'));
-        @refs = ((join(' ', @refs)) =~ /<([^>]+)>/g);
+        my @refs = (($hdr->header_raw('References') || '') =~ /<([^>]+)>/g);
+        push(@refs, (($hdr->header_raw('In-Reply-To') || '') =~ /<([^>]+)>/g));
          while (defined(my $irt = pop @refs)) {
                  next if $mid{"<$irt>"};
                  return $irt;