diff --git a/opac/opac-ISBDdetail.pl b/opac/opac-ISBDdetail.pl
index 175d3465ce..f341884377 100755
--- a/opac/opac-ISBDdetail.pl
+++ b/opac/opac-ISBDdetail.pl
@@ -174,7 +174,7 @@ for my $itm (@items) {
         && !$itemtypes->{$itm->{'itype'}}->{notforloan}
         && $itm->{'itemnumber'};
 
-    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed($itm, $patron->unblessed)
+    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed( $itm, ( $patron ? $patron->unblessed : {} ) )
       unless $allow_onshelf_holds;
 }
 
diff --git a/opac/opac-MARCdetail.pl b/opac/opac-MARCdetail.pl
index d758af2891..115e8fd9e8 100755
--- a/opac/opac-MARCdetail.pl
+++ b/opac/opac-MARCdetail.pl
@@ -127,9 +127,9 @@ if(my $cart_list = $query->cookie("bib_list")){
 }
 
 my $allow_onshelf_holds;
-my $patron = Koha::Patrons->find( $loggedinuser )->unblessed;
+my $patron = Koha::Patrons->find( $loggedinuser );
 for my $itm (@all_items) {
-    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed($itm, $patron);
+    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed( $itm, ( $patron ? $patron->unblessed : {} ) );
     last if $allow_onshelf_holds;
 }
 
diff --git a/opac/opac-detail.pl b/opac/opac-detail.pl
index a56ed6a96b..ed8a5d56aa 100755
--- a/opac/opac-detail.pl
+++ b/opac/opac-detail.pl
@@ -668,7 +668,7 @@ if ( not $viewallitems and @items > $max_items_to_display ) {
         && !$itemtypes->{$itm->{'itype'}}->{notforloan}
         && $itm->{'itemnumber'};
 
-    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed( $itm, $patron->unblessed )
+    $allow_onshelf_holds = C4::Reserves::OnShelfHoldsAllowed( $itm, ( $patron ? $patron->unblessed : {} ) )
       unless $allow_onshelf_holds;
 
     # get collection code description, too