diff --git a/acme-tinier.pl b/acme-tinier.pl
index 0ed35e2..266e4ac 100755
--- a/acme-tinier.pl
+++ b/acme-tinier.pl
@@ -134,7 +134,7 @@ for my $domain (@domains) {
 
 	my ($challenge) = grep { $_->{type} eq 'http-01' }
 		@{$json->decode($result)->{challenges}};
-	my $token = $challenge->{token} =~ s/[^A-Za-z0-9_-]/_/r;
+	my $token = $challenge->{token} =~ s/[^A-Za-z0-9_-]/_/gr;
 	my $key_auth = "$token.$thumbprint";
 	my $known_path = "$acme_dir/$token";