diff --git a/opac/opac-shelves.pl b/opac/opac-shelves.pl
index 76d632a785..ef418e0901 100755
--- a/opac/opac-shelves.pl
+++ b/opac/opac-shelves.pl
@@ -72,13 +72,13 @@ if ( $op eq 'add_form' ) {
     if ( $loggedinuser ) {
         eval {
             $shelf = Koha::Virtualshelf->new(
-                {   shelfname          => $query->param('shelfname'),
-                    sortfield          => $query->param('sortfield'),
-                    category           => $query->param('category') || 1,
-                    allow_add          => $query->param('allow_add'),
-                    allow_delete_own   => $query->param('allow_delete_own'),
-                    allow_delete_other => $query->param('allow_delete_other'),
-                    owner              => $loggedinuser,
+                {   shelfname          => scalar $query->param('shelfname'),
+                    sortfield          => scalar $query->param('sortfield'),
+                    category           => scalar $query->param('category') || 1,
+                    allow_add          => scalar $query->param('allow_add'),
+                    allow_delete_own   => scalar $query->param('allow_delete_own'),
+                    allow_delete_other => scalar $query->param('allow_delete_other'),
+                    owner              => scalar $loggedinuser,
                 }
             );
             $shelf->store;
diff --git a/virtualshelves/shelves.pl b/virtualshelves/shelves.pl
index 74e31e4380..eab6c17f70 100755
--- a/virtualshelves/shelves.pl
+++ b/virtualshelves/shelves.pl
@@ -65,13 +65,13 @@ if ( $op eq 'add_form' ) {
 } elsif ( $op eq 'add' ) {
     eval {
         $shelf = Koha::Virtualshelf->new(
-            {   shelfname          => $query->param('shelfname'),
-                sortfield          => $query->param('sortfield'),
-                category           => $query->param('category'),
-                allow_add          => $query->param('allow_add'),
-                allow_delete_own   => $query->param('allow_delete_own'),
-                allow_delete_other => $query->param('allow_delete_other'),
-                owner              => $query->param('owner'),
+            {   shelfname          => scalar $query->param('shelfname'),
+                sortfield          => scalar $query->param('sortfield'),
+                category           => scalar $query->param('category'),
+                allow_add          => scalar $query->param('allow_add'),
+                allow_delete_own   => scalar $query->param('allow_delete_own'),
+                allow_delete_other => scalar $query->param('allow_delete_other'),
+                owner              => scalar $query->param('owner'),
             }
         );
         $shelf->store;