diff --git a/opac/opac-search.pl b/opac/opac-search.pl
index 2dcb218dc7..57d0786742 100755
--- a/opac/opac-search.pl
+++ b/opac/opac-search.pl
@@ -597,8 +597,8 @@ if ($tag) {
     my $json = JSON->new->utf8->allow_nonref(1);
     $pasarParams .= '&query=' . uri_escape_utf8( $json->encode($query) );
     $pasarParams .= '&count=' . uri_escape_utf8($results_per_page);
-    $pasarParams .= '&simple_query=' . uri_escape_utf8($simple_query);
-    $pasarParams .= '&query_type=' . uri_escape_utf8($query_type) if ($query_type);
+    $pasarParams .= '&simple_query=' . uri_escape_utf8($simple_query) if $simple_query;
+    $pasarParams .= '&query_type=' . uri_escape_utf8($query_type)     if ($query_type);
     my $itemtypes_nocategory =
         { map { $_->{itemtype} => $_ } @{ Koha::ItemTypes->search_with_localization->unblessed } };
     eval {