diff --git a/ui/src/views/network/FirewallRules.vue b/ui/src/views/network/FirewallRules.vue
index 787f5c2d8e2e..2d19bdd1f93a 100644
--- a/ui/src/views/network/FirewallRules.vue
+++ b/ui/src/views/network/FirewallRules.vue
@@ -404,6 +404,9 @@ export default {
     addRule () {
       if (this.loading) return
       this.loading = true
+      if (this.newRule.cidrlist == null || this.newRule.cidrlist.trim?.() === '') {
+        delete this.newRule.cidrlist
+      }
       api('createFirewallRule', { ...this.newRule }).then(response => {
         this.$pollJob({
           jobId: response.createfirewallruleresponse.jobid,