lib/PublicInbox/SolverGit.pm | 3 ++-

diff --git a/lib/PublicInbox/SolverGit.pm b/lib/PublicInbox/SolverGit.pm
index 1b1951b58e17a733f4396f258dcfac93abc0b7c0..d9b312c18d2f155ae39c417f60830395c58e3e9e 100644
--- a/lib/PublicInbox/SolverGit.pm
+++ b/lib/PublicInbox/SolverGit.pm
@@ -286,7 +286,8 @@ }
 
 sub extract_old_mode ($) {
 	my ($di) = @_;
-	if (grep(/\Aold mode (100644|100755|120000)$/, @{$di->{hdr_lines}})) {
+	if (join('', @{$di->{hdr_lines}}) =~
+			/^old mode (100644|100755|120000)\b/) {
 		return $1;
 	}
 	'100644';