diff --git a/Koha/REST/V1/Cities.pm b/Koha/REST/V1/Cities.pm
index d9d2774f6b..e8ababe10a 100644
--- a/Koha/REST/V1/Cities.pm
+++ b/Koha/REST/V1/Cities.pm
@@ -30,8 +30,9 @@ sub list {
 
     my $cities;
     my $filter;
+    $args //= {};
 
-    for my $filter_param ( keys $args ) {
+    for my $filter_param ( keys %$args ) {
         $filter->{$filter_param} = { LIKE => $args->{$filter_param} . "%" };
     }