lib/PublicInbox/WWW.pm |  4 +++-
 t/plack.t              | 25 ++++++++++++++++++++++++-

diff --git a/lib/PublicInbox/WWW.pm b/lib/PublicInbox/WWW.pm
index 411db16f4eaffaaee7f788b0fb356d3751884ffd..d5635d849fcea047c0402f22cacbdab87ce913ea 100644
--- a/lib/PublicInbox/WWW.pm
+++ b/lib/PublicInbox/WWW.pm
@@ -47,7 +47,9 @@ 		msg_page($ctx, $1, $2, $3);
 
 	# in case people leave off the trailing slash:
 	} elsif ($path_info =~ m!$LISTNAME_RE/$MID_RE/(f|T|t)\z!o) {
-		r301($ctx, $1, $2, $3 eq 't' ? 't/#u' : $3);
+		my ($listname, $mid, $suffix) = ($1, $2, $3);
+		$suffix .= $suffix =~ /\A[tT]\z/ ? '/#u' : '/';
+		r301($ctx, $listname, $mid, $suffix);
 
 	# convenience redirects order matters
 	} elsif ($path_info =~ m!$LISTNAME_RE/([^/]{2,})\z!o) {
diff --git a/t/plack.t b/t/plack.t
index f61b3bec8afb7423cfaf9f31e253922b1b106199..b77cdba552c516ecaabe3b757d8f732ea75b5865 100644
--- a/t/plack.t
+++ b/t/plack.t
@@ -81,6 +81,30 @@ 		is(301, $res->code, 'is permanent redirect');
 		is($to, $res->header('Location'), 'redirect location matches');
 	});
 
+	my $pfx = 'http://example.com/test';
+	foreach my $t (qw(t T)) {
+		test_psgi($app, sub {
+			my ($cb) = @_;
+			my $u = $pfx . "/blah%40example.com/$t";
+			my $res = $cb->(GET($u));
+			is(301, $res->code, "redirect for missing /");
+			my $location = $res->header('Location');
+			like($location, qr!/\Q$t\E/#u\z!,
+				'redirected with missing /');
+		});
+	}
+	foreach my $t (qw(f)) {
+		test_psgi($app, sub {
+			my ($cb) = @_;
+			my $u = $pfx . "/blah%40example.com/$t";
+			my $res = $cb->(GET($u));
+			is(301, $res->code, "redirect for missing /");
+			my $location = $res->header('Location');
+			like($location, qr!/\Q$t\E/\z!,
+				'redirected with missing /');
+		});
+	}
+
 	test_psgi($app, sub {
 		my ($cb) = @_;
 		my $atomurl = 'http://example.com/test/new.atom';
@@ -92,7 +116,6 @@ 		like($res->content, qr!href="blah%40example\.com/"!,
 			'index generated');
 	});
 
-	my $pfx = 'http://example.com/test';
 	test_psgi($app, sub {
 		my ($cb) = @_;
 		my $res = $cb->(GET($pfx . '/atom.xml'));