diff --git a/src/models/cfg.go b/src/models/cfg.go
index ab31568..abec549 100644
--- a/src/models/cfg.go
+++ b/src/models/cfg.go
@@ -25,6 +25,11 @@ func (wl Whitelist) Insert(cfg config.Config) (err error) {
 	exists, _ := cfg.Db.Get(&w)
 	if exists {
 		existing, _ := GetWhitelists(cfg)
+		for _, j := range existing {
+			if j == wl.IP {
+				return fmt.Errorf("ip %s already in config", j)
+			}
+		}
 		existing = append(existing, wl.IP)
 		w.Value = strings.Join(existing, ",")
 		cfg.Db.ID(w.ID).Update(&w)