lib/PublicInbox/Feed.pm | 8 ++++++--
 t/feed.t                | 5 +++--

diff --git a/lib/PublicInbox/Feed.pm b/lib/PublicInbox/Feed.pm
index a8578e760fdf8cc002e8ad53d9a008879ee4bff0..2dc3940ff7e4fc3bd591f5501eb40f53792fb112 100644
--- a/lib/PublicInbox/Feed.pm
+++ b/lib/PublicInbox/Feed.pm
@@ -36,7 +36,7 @@ 			rel => 'self',
 			href => $feed_opts->{atomurl} ||
 				"http://example.com/atom.xml",
 		},
-		id => $addr || 'public-inbox@example.com',
+		id => 'mailto:' . ($addr || 'public-inbox@example.com'),
 		updated => POSIX::strftime(DATEFMT, gmtime),
 	);
 
@@ -278,13 +278,17 @@
 	my $date = $mime->header('Date');
 	$date = PublicInbox::Hval->new_oneline($date);
 	$date = feed_date($date->raw) or return 0;
+	$add =~ tr!/!!d;
+	my $h = '[a-f0-9]';
+	my (@uuid5) = ($add =~ m!\A($h{8})($h{4})($h{4})($h{4})($h{12})!o);
+
 	$feed->add_entry(
 		author => { name => $name, email => $email },
 		title => $subject,
 		updated => $date,
 		content => { type => "html", content => $content },
 		link => $midurl . $href,
-		id => $add,
+		id => 'urn:uuid:' . join('-', @uuid5),
 	);
 	1;
 }
diff --git a/t/feed.t b/t/feed.t
index a6bffdcd830a0e3c18a63d7a641b83f77af3b0b1..880716ccb4a3df9e1c0c6b6c30303542ca179894 100644
--- a/t/feed.t
+++ b/t/feed.t
@@ -58,7 +58,7 @@ 			skip 'XML::Feed missing', 2 unless $have_xml_feed;
 			my $p = XML::Feed->parse(\$feed);
 			is($p->format, "Atom", "parsed atom feed");
 			is(scalar $p->entries, 3, "parsed three entries");
-			is($p->id, 'public-inbox@example.com',
+			is($p->id, 'mailto:public-inbox@example.com',
 				"id is set to default");
 		}
 
@@ -142,7 +142,8 @@ 		});
 		SKIP: {
 			skip 'XML::Feed missing', 3 unless $have_xml_feed;
 			my $p = XML::Feed->parse(\$feed);
-			is($p->id, 'a@example.com', "ID is set correctly");
+			is($p->id, 'mailto:a@example.com',
+				"ID is set correctly");
 			is($p->format, "Atom", "parsed atom feed");
 			is(scalar $p->entries, 3, "parsed three entries");
 		}