lib/PublicInbox/Feed.pm | 2 +-

diff --git a/lib/PublicInbox/Feed.pm b/lib/PublicInbox/Feed.pm
index a04838a1a608948cbc096af61413337bd0f9444e..ae07189504327530290eb986bede736ae25c25cd 100644
--- a/lib/PublicInbox/Feed.pm
+++ b/lib/PublicInbox/Feed.pm
@@ -102,7 +102,7 @@
 	my $hex = '[a-f0-9]';
 	my $addmsg = qr!^:000000 100644 \S+ (\S+) A\t${hex}{2}/${hex}{38}$!;
 	my $delmsg = qr!^:100644 000000 (\S+) \S+ D\t(${hex}{2}/${hex}{38})$!;
-	my $refhex = qr/(?:HEAD|${hex}{4,40})(?:~\d+)?/;
+	my $refhex = qr/(?:HEAD|${hex}{4,40})(?:~[0-9]+)?/;
 
 	# revision ranges may be specified
 	my $range = 'HEAD';