diff --git a/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs b/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
index 5a76ab56..7a16dd8f 100644
--- a/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
+++ b/v2rayN/ServiceLib/Services/CoreConfig/CoreConfigSingboxService.cs
@@ -1950,13 +1950,15 @@ public class CoreConfigSingboxService
         //convert route geosite & geoip to ruleset
         foreach (var rule in singboxConfig.route.rules.Where(t => t.geosite?.Count > 0).ToList() ?? [])
         {
-            rule.rule_set = rule?.geosite?.Select(t => $"{geosite}-{t}").ToList();
+            rule.rule_set ??= new List<string>();
+            rule.rule_set.AddRange(rule?.geosite?.Select(t => $"{geosite}-{t}").ToList());
             rule.geosite = null;
             AddRuleSets(ruleSets, rule.rule_set);
         }
         foreach (var rule in singboxConfig.route.rules.Where(t => t.geoip?.Count > 0).ToList() ?? [])
         {
-            rule.rule_set = rule?.geoip?.Select(t => $"{geoip}-{t}").ToList();
+            rule.rule_set ??= new List<string>();
+            rule.rule_set.AddRange(rule?.geoip?.Select(t => $"{geoip}-{t}").ToList());
             rule.geoip = null;
             AddRuleSets(ruleSets, rule.rule_set);
         }
@@ -1964,12 +1966,14 @@ public class CoreConfigSingboxService
         //convert dns geosite & geoip to ruleset
         foreach (var rule in singboxConfig.dns?.rules.Where(t => t.geosite?.Count > 0).ToList() ?? [])
         {
-            rule.rule_set = rule?.geosite?.Select(t => $"{geosite}-{t}").ToList();
+            rule.rule_set ??= new List<string>();
+            rule.rule_set.AddRange(rule?.geosite?.Select(t => $"{geosite}-{t}").ToList());
             rule.geosite = null;
         }
         foreach (var rule in singboxConfig.dns?.rules.Where(t => t.geoip?.Count > 0).ToList() ?? [])
         {
-            rule.rule_set = rule?.geoip?.Select(t => $"{geoip}-{t}").ToList();
+            rule.rule_set ??= new List<string>();
+            rule.rule_set.AddRange(rule?.geoip?.Select(t => $"{geoip}-{t}").ToList());
             rule.geoip = null;
         }
         foreach (var dnsRule in singboxConfig.dns?.rules.Where(t => t.rule_set?.Count > 0).ToList() ?? [])