diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-sendshelfform.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-sendshelfform.tt
index 71d6a2b1b2..b126018c57 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-sendshelfform.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-sendshelfform.tt
@@ -41,6 +41,7 @@
                                         <textarea id="comment" name="comment" rows="4" cols="40" class="form-control"></textarea>
 
                                         <input type="hidden" name="shelfid" value="[% shelfid | html %]" />
+                                        <input type="hidden" name="op" value="cud-send" />
                                     </fieldset>
                                     [% IF Koha.Preference('OPACHoldRequests') || Koha.Preference('OpacRenewalAllowed') %]<p id="donotrequestbymail">Please do not use this mail to request or renew books.</p>[% END %]
                                     <fieldset class="action">
diff --git a/opac/opac-sendshelf.pl b/opac/opac-sendshelf.pl
index e08b474cb1..2f3cf07961 100755
--- a/opac/opac-sendshelf.pl
+++ b/opac/opac-sendshelf.pl
@@ -54,10 +54,11 @@ my ( $template, $borrowernumber, $cookie ) = get_template_and_user(
 
 my $shelfid = $query->param('shelfid');
 my $email   = $query->param('email');
+my $op      = $query->param('op') // q{};
 
 my $shelf = Koha::Virtualshelves->find($shelfid);
 if ( $shelf and $shelf->can_be_viewed($borrowernumber) ) {
-    if ($email) {
+    if ( $email && $op eq 'cud-send' ) {
         my $comment = $query->param('comment');
 
         my $patron     = Koha::Patrons->find($borrowernumber);