--- a/build-aux/update-copyright
+++ b/build-aux/update-copyright
@@ -124,7 +124,7 @@
 use warnings;
 
 my $copyright_re = 'Copyright';
-my $circle_c_re = '(?:\([cC]\)|@copyright{}|©)';
+my $circle_c_re = '(?:\([cC]\)|@copyright\{\}|©)';
 my $holder = $ENV{UPDATE_COPYRIGHT_HOLDER};
 $holder ||= 'Free Software Foundation, Inc.';
 my $prefix_max = 5;