diff --git a/admin/smart-rules.pl b/admin/smart-rules.pl
index 64c86aa3fc..ea3b1df3dd 100755
--- a/admin/smart-rules.pl
+++ b/admin/smart-rules.pl
@@ -289,7 +289,7 @@ elsif ($op eq 'add') {
     my $opacitemholds = $input->param('opacitemholds') || 0;
     my $article_requests = $input->param('article_requests') || 'no';
     my $overduefinescap = $input->param('overduefinescap') || '';
-    my $cap_fine_to_replacement_price = $input->param('cap_fine_to_replacement_price') eq 'on';
+    my $cap_fine_to_replacement_price = ($input->param('cap_fine_to_replacement_price') || '') eq 'on';
     my $note = $input->param('note');
     $debug and warn "Adding $br, $bor, $itemtype, $fine, $maxissueqty, $maxonsiteissueqty, $cap_fine_to_replacement_price";