diff --git a/koha-tmpl/intranet-tmpl/prog/js/vue/components/Admin/CirculationTriggers/CirculationTriggersFormAdd.vue b/koha-tmpl/intranet-tmpl/prog/js/vue/components/Admin/CirculationTriggers/CirculationTriggersFormAdd.vue
index 44c8894e89..ddc0f4fcda 100644
--- a/koha-tmpl/intranet-tmpl/prog/js/vue/components/Admin/CirculationTriggers/CirculationTriggersFormAdd.vue
+++ b/koha-tmpl/intranet-tmpl/prog/js/vue/components/Admin/CirculationTriggers/CirculationTriggersFormAdd.vue
@@ -688,7 +688,7 @@ export default {
             this.triggerNumber =
                 this.editMode === "edit"
                     ? triggerNumber
-                    : this.triggerCounts[library_id] + 1;
+                    : (this.triggerCounts[library_id] ?? 0) + 1;
         },
         setFallbackRuleSet() {
             this.fallbackRuleSet = {